Wow...I'm honored to share the forum with you.  I've been looking into the history of digital currency and I have great respect for how clever hashcash is (shouldn't we be using it by now?).  Thank you for providing links to our very poorly understood and under appreciated history.

Brian

PS -- just read your newbie intro post. Too funny. People like you get white listed upon request around here!

Are you sending more than a $1? More than ฿1?

There are many tens of billions of XRP...why are people buying them?

Full disclosure, I sold the vast majority of mine for ฿2.5.

There are like, what, 80 billion XRP? Roughly 8,000 XRP per currently existing bitcoin.  If XRP value as a currency equaled Bitcoin, then I guess it makes sense to buy 35,000 XRP for 2.5 bitcoins. But, XRP isn't a currency really, right?

I'll admit to not fully understanding ripple.  I think the IOU idea is very interesting, but skeptical that mixing friends, family, and money will work out well.

Looks like a complicated transaction...funds in an exchange get dispersed?

Tip? Perhaps someone like a post?

What intrinsic value does a car key have? It's useful for driving, but intrinsically worthless.

+1. Well played

There have been many attempts in the past at making digital currencies. Bitcoin has a very different validation/double spending prevention/redemption model than anything before it. While I don't think Bitcoin will fail, I do think future modifications to the protocol will determine how likely it is to be widely adopted.

So do you mean to have a signed, valid, but not transmitted emergency transaction sending all of your funds to a new address not in your wallet (For which you have a private key stored elsewhere)?

This would set up a race condition where whoever gets their transaction into a block first wins.  Since change addresses are precomputed and stored in the wallet, you would need to create an address outside of your wallet carefully.

Alternatively, what if they stole the target address private key? Then you would have no way to spend your funds safely.

The Bitcoin protocol does have a method of sending funds to an IP address and the computer at the IP address will supply the recipient address... So, in theory, the private/public key pair of the destination address need not be created yet.

You could register an account with a large mining pool (who could get your send to IP address transaction in a block quickly) to create the recipient address and store the private key for you and handover the funds when the incoming coins from the addresses you had told them they would come from arrived.

I'm putting together a lecture on the pre-history of Bitcoin for the Bitcoin Education Project (btcedproject.org). Digital currency has been heavily researched since the 1980's (including DARPA funded groups). For some background reading, this book is good (start on page 230-ish):

http://search.barnesandnoble.com/Trust-and-Risk-in-Internet-Commerce/L-Jean-Camp/e/9780262531979/?itm=7&USRI=l+jean+camp

I suppose you could do it socially...ie, only known friends can join the club. But that kind of like centralization in and of itself.

How do you validate new users/miners? Consensus is what occurs after you decide on validation parameters...what stops Corporation X from hiring 25,000 stooges?

This is the part I find confusing; inputs are different than addresses?  I suppose they must be, by what you're saying.  

What if the change address was the same as the sending address?

The answer has got to be no...right?  I mean, I could scan the block chain and look for all repeatable transactions and wreak no small amount of havoc otherwise...

That sure would teach folks not to re-use addresses!

My apologies if this is the wrong forum.

If I send money to Bob using my 1SendtoBobAddressL0r3mIp5umD0lr address and Alice sends me money to that same address, could Bob rebroadcast my raw transaction to get double paid?

So, S=n^2/650

It will be interesting to see if this parameter pops up naturally in some equation somewhere.

You could raise any term to any power...why pick the ones you did?

Yup, it gets stored. It'll be there when you get back . The recipient address does not need to be anything other than a well formed address. In fact, the recipient address doesn't even have to belong to someone...see 1bitcoineater

http://blockexplorer.com/address/1BitcoinEaterAddressDontSendf59kuE

This vanity address is so long, there is no way someone knows the corresponding private key. Money sent here is just plain old lost.

Limits on the block size, IMHO, should be determined by the market with some temporary fail-safe stuff hard-wired into the code and updated as needed (like our current block chain protecting max block size).

If a miner wants no other transactions in a block (and forego the associated transaction fees), so be it. When the block limit has a reason to be set above 1 MB, it'll be up to miners to use that extra space in the block as they see fit.

Is the zero transaction block not an expression of market forces? I mean, if I want to charge high fees, I can artificially limit transactions by mining lots of blank blocks.