Just one example.  http://shinybars.com/t/paymentoptions

Simplified you have three options:
CC = fast + 3% more expensive
"Bank stuff" = slow + 3% cheaper
Bitcoin = fast + 3% cheaper

Edit: you may already know some of this the post became more of a general guide as I kept type.

So a couple things. The first is that in the use despite the common usage of "110" or "220" nominal voltage is 120 & 240.  You should however stick a multimeter into an outlet to find out.  You can test a 120V outlet, the 240V is going to be double that.  Unless you are at the far end of distribution the measured voltage at the outlet is probably closer to 120/240 then 110 /120.  Still you should adjust the power capacity numbers based off your actual voltage.

The second is that the 24A per PDU already includes the derate.  The circuit (30A breaker, 10AWG wiring, NEMA L6-30R outlet) is rated for 30A peak load.  Continual load is derated to 80% of that so 30A * 0.8 = 24A.  A code compliant circuit using a NEMA L6-30R receptacle (proper name for "outlet", outlets are actually on the PDU) is good for 24A continual or 30A peak.  That is why the PDU lists 24A, you don't have to further derate that.  Putting it together with 240V means each PDU is good for 5.76KW of power per pdu.

Third.  I am sure you have double checked but most PDU don't use C19 connectors.  I assume your server PDU is "beefy" and pulls more than 12A?  Just don't want someone ready briefly to be confused.  Almost all PSU have a C13 connector.  PDU have a C14 connector so the cable most people will need is one C13 to C14 cable per device. 

Are there other options? 
Well there are but I think you find any other option is either more expensive or not up to code. 240V, 30A circuit just comes down to the most economical choice.  The used PDUs are dirt cheap, the outlets are nothing "exotic" (even home depot probably carries a NEMA L6-30R is look hard enough) and while 10AWG isn't "fun" to work with it is still a lot easier to manage then the larger cables.  For example the standard connector for a 50A circuit is a NEMA L6-50R which doesn't exist except on paper, as safer pin and sleeve solutions are used. One common alternative is the California standard (become widely used in movie industry) http://www.stayonline.com/detail.aspx?id=6272 

Yeah that is the plug only.  $70.  A matching outlet is another $50 to $70.  To make a custom cable which converts a 50A connector into 2x NEMAL L6-30 plus the 50A outlet is probably going to run you $250+.   So I am not saying "the 30A route" is the only possible way to deliver power, I am just saying trust me I did the research and cost per KW you aren't going to find a cheaper, code compliant solution then using 240V 30A circuits and 30A (derated to 24A) used PDUs. 

So if you need <5.76KW of power.  Install one 30A breaker, make one 10AWG run, install one NEM L6-30R outlet, and get one matching PDU*.
So if you need <11.52KW of power.  Install two 30A breakers, make two 10AWG run, install two NEM L6-30R outlets, and get two matching PDUs*.
So if you need <17.28KW of power.  Install three 30A breakers, make three 10AWG run, install three NEM L6-30R outlets, and get three matching PDUs*.
So if you need <23.04KW of power.  Install four 30A breakers, make four 10AWG run, install four NEM L6-30R outlets, and get four matching PDUs*.
...

* I recommend using the APC AP9571.  There is nothing magical about it but APC made millions of them so there are tons of used ones on ebay for dirt cheap.


An ebay listing may say 208V but it works fine at 240V as well (datacenters are usually 208V which is why it lists that).
30A, 24A derated (5.76KW usable)
NEMA L6-30P plug to match your economical NAM L6-30R recptacle.
Has twelve C14 outlets.
Just get some C14 to C13 cables from amazon or monoprice (<$5 ea) to connect from the PDU to each PSU.

If the distance from your breaker panel to where your rigs (and NEMA L6-30R receptacles) is long you may want to consider a subpanel.  How this would work is that in your main panel one or more high current breakers is used and a single run with large gauge wire is run to a sub panel located near the rigs.   The sub panel then has say 6 30A breakers and short 10 AWG runs to NEMA L6-30R receptacles.

If you go another route just remember you can pull the full rated current of the PDU (as it has already been derated).  However the circuit (receptacle, wiring, and breaker) has to be designed such that the continual load is only 80% of the circuit peak capacity. Some PDU labels will list both capacities (30A, 24A derated).  This is why you will find PDUs generally are 12, 16, 24, or 40 Amps.

12A PDU is 80% of a 15A circuit (15A outlet, wiring, and breaker)
16A PDU is 80% of a 20A circuit (20A outlet, wiring, and breaker)
24A PDU is 80% of a 30A circuit (30A outlet, wiring, and breaker)  <- The sweet spot in terms of $/KW installed
40A PDU is 80% of a 50A circuit (50A outlet, wiring, and breaker)

Another piece of advice is to start small (i.e. start with enough gear to fill one 5.76KW "unit").  Speaking from personal experience when you start getting into the tens of KW of power range everything becomes more of a challenge especially cooling.  It is much easier to design a single efficient layout (say half a rack) and then scale out, rather than buying gear needing 30KW+ and then realizing the engineering, power, and cooling challenges are no joke.

I don't need a tip (I got a coin or two in the ole wallet.dat), glad to help for free.  My miner days are likely coming to a close so I will need to mine vicariously.

<shamless plug mode>
If you absolutely feel the need to help ...  consider https://bitSimple.com next time you need to sell some coins to pay that electric bill.
</shameless plug mode>

The handling of tx fee is a pretty ingenious solution.  The tx fee and the miner reward are loosely coupled.

There is one potential concern, since tx fees are implied not explicitly defined, a bug in a client could result in a loss of coins for a user.

For example say a flawed client created this tx:
TxIn0 (value 100 BTC)
TxOut0 (value 1 BTC)
TxOut1 (value 9 BTC)

You just paid 90 BTC as a fee to miners.  Likewise a flawed miner could actually "erase" coins permanently.  If the sum of all txs in a block is 1 BTC and the block reward is 25 BTC but due to a bug the miner makes the coinbase tx 25.1 BTC then the money supply would be reduced by 0.9 BTC permanently.

The major clients are at this point pretty extensively tested so the risk is more in custom implementations or using the rawtx RPC call (which is very low level and will let you do lots of dangerous things).

Bitcoin likely can't be changed at this point however for an altcoin the only (hindsight being 20/20) changes I would recommend would be:
a) make the tx fee explicitly defined in the tx header and thus a tx is invalid if the sum(inputs) =/= sum(outputs) + txfee
b) make a block invalid if coinbase =/= sum(tx_fees) + current_block_subsidy

While that will work they make cords which have the correct connectors on each end.  As pointed out above you just need a C13 to C14 cord.  It is pretty common in datacenters.   Almost all electronics (like your ATX PSU) have C14 inlet, and PDU have C13 outlet.  So a single cord is used for everything.  Servers, switches, routers, firewalls, etc.

For amazon:
http://www.amazon.com/Tripp-Lite-P004-004-18AWG-Connectors/dp/B003MG9F78/ref=sr_1_2?s=electronics&ie=UTF8&qid=1390094044&sr=1-2&keywords=C13+to+C14

This is just an example I typed "C13 to C14" there may be (and likely is a cheaper, better version) but the cable one needs to go from PDU to PSU without any adapters is a C13 to C14 cable.

It is complicated and probably better to look at the code directly as trying to explain it in English at a high level abstracts some of it away so while this gets you closer it may still leave some parts ambiguous.  The second image is closer to the correct scenario however remember a tx can have multiple inputs as well.

A hash of the simplified transaction consisted of a SINGLE INPUT and ALL outputs is created, this is then signed by the private key for that input and stored in the "sig & pubkey" portion of that tx input.  
See here: https://en.bitcoin.it/w/images/en/e/e1/TxBinaryMap.png  

Bitcoin has no concept of "owners" or "wallets" so the change output isn't special, it is an output just like any other.  If you are going to create an illustration for explaining then creating one with only a single input is a poor choice because the next questions becomes how to dI handle n inputs where n >1.  An example with 2 inputs is better because 3, 20, or 4,000 inputs are handled exactly the same as 2.  

The other thing you need to divorce yourself from is you aren't sending funds from a public key, you are using a SPECIFIC unspent output of a prior tx as an input.  Yes in conversation we may say "he paid me from address 123..." but when trying to explain Bitcoin's working that falls apart and trying to understand anything becomes impossible.  An input is a specific unspent output.  It is referred to (in the Tx input) by the tx hash (of the prior tx) and index (which output of that tx is being used here).

So in more general form.   Lets assume you have a tx which consists of 3 unspent outputs (which become inputs for this tx) A, B, C and two new outputs Y & Z (it doesn't matter if one of these is a change address or you just happened to pay two different receivers with the exact amount of coins, an inputs is an input and an output is an output).

First the output scripts are created.  The "normal" Bitcoin tx is a PayToPubKeyHash, so likely the user provided you a Bitcoin Address.  This is reversed into the PubKeyHash and a script which locks that output of a specific value to a specific PubKeyHash is created.  The outputs are arranged in a sequence randomly (to avoid leaking which one is the "change").  Lets say Z become TxOut0 and Y becomes TxOut1.  The inputs are then arranged in a sequence randomly.  Lets say A becomes TxIn0, B becomes TxIn1, and C becomes TxIn2.

We now have a tx which looks like this:
TxIn0
Txin1
TxIn2
TxOut0
TxOut1


A simplified version of the tx is created (TxIn0, TxOut0, TxOut1) and hashed.  The hash is signed by the private key for A and stored in the Sig & PubKey section for TxIn0.
A simplified version of the tx is created (TxIn1, TxOut0, TxOut1)and hashed.  The hash is signed by the private key for B and stored in the Sig & PubKey section for TxIn1.
A simplified version of the tx is created (TxIn2, TxOut0, TxOut1) and hashed.  The hash is signed by the private key for C and stored in the Sig & PubKey section for TxIn2.

One last thing which may not be obvious.  There is no 1:1 relationship between inputs and private keys.  For example if you have two unspent outputs to the same address (say A & C) then they share the same private key however they are still unique and discrete inputs so the tx above would still have 3 inputs.

I likely am overlooking or misstating something here so I would double check all this against the code.

A key component of Bitcoin is a fixed money supply.  You can't do that if you issue new coins forever.  Now you could keep the block reward at 50 BTC and just go 50 BTC to zero like a car hitting a brick wall at 100 mph and hope the network can handle it.  The subsidy halving gives the Bitcoin "economy" time to adapt to being supported by transaction fees.

In theory you "could" have a crypto currency without a fixed money supply.  You couldn't say things like no more than 21M coins will ever be created but on a long enough timeline the difference between <1% annual money supply growth and <1% annual money supply reduction is minimal.  Of course changing the rule after the fact would be unethical.

bitcoin.org

Simple. Mining doesn't ever stop.  As long as there is Bitcoin there will be mining.

If blockexplorer (or blockchain.info) shows no activity then the answer is simple ... nothing has been sent.

If someone doesn't send you coins there is nothing your wallet can do to make them appear.

What is to stop someone from selling condoms with holes in them marketed to people who want to have children?

99% of USD are ALREADY digital and centrally controlled.  What point is there in a decentralized centrally controlled currency?

This.  The concept of a trust web is very decentralized and open however the default trust web essentially undermines the entire system as given the "easy way out" most users will simply use the default.  Now one could argue well it doesn't matter what other people do but that is simplistic.   If a super super super majority of users trust the default trust (because they never decided to educate themselves) then for a persons interaction with those users all that matters is what the default trust thinks, nothing more, nothing less.

Can you link to the site because the only reference I see for a "BitCare app" doesn't use private keys, it isn't a wallet, and it simply reports balances based on addresses.

I wonder if this is an "xy problem".
http://meta.stackoverflow.com/questions/66377/what-is-the-xy-problem

It they don't have assets then they likely don't have any significant money either.  People don't just sit around with mountains of cash and no assets.   Cash continually loses value.  Other than death and taxes it is one of the certainties of life.  If fact quite a few people have a negative net worth which means in a currency failure their negative networth would rapidly approach zero (a net improvement).

Wait how did I miss this event?  Using CP as a weapon?  That is pretty low.   I have no love for pool hopper but they merely exploit the poorly constructed rules of prop pools.  A good thing IMHO as it has driven those pools (mostly) out of existence replaced with fairer distribution systems.

I think you might be equating wealth with money.  Money makes up a small portion of the average persons wealth.  Property, stocks, real estate, etc would still have value in a currency collapse. 

That is possible but they are going to stop all business and wait 6-9 months?   For a license they may or may not need?
By definition apply for a license (a defacto admission that unlicensed activity is unlawful) while engaging in unlicensed activity is not smart.   I can't see any state granting a license to an entity which is operating without a license while seeking said license.  The time required to obtain a license is an obstacle.


Not sure what you mean by this.  There is no unified list but pretty much all states make licensure a public record and most (all? I want to say all but there may be one or two exceptions) make these records available online.  If xyz claims to be a licensed money transmitter, license #12345679 it is pretty hard to verify if there is no way to verify.

Examples:
CA money transmitters: http://www.dbo.ca.gov/Licensees/money_transmitters/money_transmitters_directory.asp
VA money transmitters: http://www.scc.virginia.gov/bfi/reg_inst/trans.pdf
NY money transmitters: http://www.dfs.ny.gov/about/whowesupervise/simoneyt.htm

Pretty much just google "[name of state] money transmitter" and you can find a list within a link or two.

Well the US isn't the entire world, the rest of the world doesn't really care how dysfunctional the US regulatory structure is.  So I see two potential outcomes (and I should state this is my personal opinon doesn't reflect the views or intentions of my employer).  One potential outcome is that startups abandon the US market.  They operate when regulation while not non-existent is at least not an impossible burden.  The ones which are successful gain the resources to handle the large fixed overhead that MT licenses creates.

The other scenario is startups in the US comply with federal requirements, and are able to grow faster than the response from states; in essence grow to survive.

It certainly is an obstacle to growth, and innovation but progress already routes around the damaged parts of the system.  Bitcoin will survive, however the US may simple lose its status as the "tech capital" when it comes to Bitcoin related enterprises. I am not saying that is a forgone conclusion but the regulatory risk and uncertainty doesn't help.

I agree to a certain extent.  I generally oppose new regulation but the current situation is just a nightmare of asinine proportions.  They are less than 100 companies in the world which have licenses in all fifty states.  There is some legal opinion that is is easier and cheaper today, to form a new bank (or buy an existing bank or credit union) and thus bypass the entire issue because banks and credit unions are not MSBs and their national charter makes them outside the regulatory scope of most state regulations.  When it is easier to form a bank then issue a prepaid card for example you know something is wrong.

Still this has been a problem for twenty years now.  Decades before Bitcoin was even born there have been attempts to create a single national license because the current system is broken but all attempts to date have been futile.  The states certainly don't want to give up that power and control.   The existing players who have already gone through that nightmare don't want it to go away.  PayPal LOVES the excessive, asinine regulation.  It all but guarantees there will never be a PayPal direct competitor because the burden on any startup is simply too high and without a startup the risk is too much to dump the tens of millions to jump right to the next stage of the game.   The current MSB/MT regulation is a massive economic boom for the GreenDots, PayPals, and Western Unions of the world.  They will move massive sums of money in lobbying to kill any attempt that opens the flood gates for competitors.

Maybe this time will be different, it certainly is needed.

What is Coinbase and/or CampBX doing that BitInstant didn't?  You are implying those entities have state licensure as money transmitters are you?  If they did it would be pretty easy to verify yourself as that information is public record.

For example CA:  http://www.dbo.ca.gov/Licensees/money_transmitters/money_transmitters_directory.asp

The reality is that at the state level most of the regulation is simply a giant unknown at this point.   No two states have the same requirements, no two states even share the same definition of money, money transmitter, or even transmission.  Many states explicitly use the word "currency of the united states", some doesn't even include "foreign currency".   Some states limit their oversight to negotiable instruments (such as checks).   Does Bitcoin meet the regulatory definition of all states?  Maybe, doubtful but there has been no definitive statement by all state regulators ... yet.  However that cuts both ways, to my knowledge no state has said "exchanging Bitcoin isn't covered by statuatory definitions" either.

Bitcoin isn't just cutting edge technology, it is cutting edge in the legal space as well.  It probably will take decades, and countless court cases to resolve it all.   Most big (and no Bitcoin company is even close to "big" I am talking multi billion dollar company) simply get licensed everywhere it is possible to be licensed because despite the up front cost (eight figures easy) it is "cheaper" than the unknown.   Better to be licensed and not need to be then be not licensed and need to.  That simply isn't an option for ANY startup.

To my knowledge no Bitcoin related company US or foreign has a money transmitter license in all states that issue licenses to money transmitters.  I don't believe any Bitcoin startup even has a money transmitter license in a single state.  Someone correct me if I am wrong with cites from one or more state money transmitter registries.  Generally when seeking a license you are implicitly saying "yes I believe our activity is regulated and engaging in this activity without a license is criminal".  By definition that would imply you need to stop business to even attempt to seek the license.  Generally regulators don't issue licenses who are defacto breaking the law at the time they are seeking the license.