Here's a pretty good brainwallet idea, imo.

Chain all  (physical, postal) addresses  of places you lived in for at least 6 months
for the past 10 (or 20) years . One address is easily 25 bits of entropy (even within
one large country), so with 5 addresses  you are good to go.  This is something you are likely to remember for many years (likely you had to write each of the addresses many a time), and even
if you forget some of the addresses you may be able to restore them from bills, letters, etc.
Also, someone has to know you very very well to know all the addresses.
In fact, the closer the person is to you, the less information you'd need to communicate
in case of emergency or in your will.
You might want to chain  a short  password in the end  to protect you from your mom though

Won't work for very young people, or for someone who lived in the same city all their life..
but hey, it's a pretty good idea for a lot of people.

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I think there's no shame in it. If a  user doesn't want to join p2pool himself it's probably because he doesn't know how to set it up, or doesn't have resources to maintain a full copy of the blockchain. In any case, whatever reason he has  to prefer any particular pool, this reason still remains valid.

cool. (Except it screws the hashrate statistics.) I wonder why isn't it more common then. May be it'd be good to convince one of the bigger pools doing it (like ~10% hashrate), may be then smaller ones would flock in and multiply.

subj

If pools themselves were getting their work from p2pool and then distributing
it to miners, they would
- still collect user fees just as they do
- offer users strictly smaller variance of payouts

users of small pools  would
- not notice any difference except smaller variance
- not need to know anything about p2pool at all

p2pool users would be a part of a bigger pool so get smaller variance as well.

It would also lower the entry barrier for new pools. Instead of starting off with offering users 0% of the network
hashrate, they would essentially start with that of p2pool.

As a result, smaller pools would increase in number, contributing somewhat towards decentralization.

Basically the only rational reason I see that would make a miner join a large pool rather than
a small one is reduced variance. This is important if the difficulty is rising fast and the miner
needs to recover his investment in the first couple of months (or never). The idea above solves this problem(I think).

Sure all winnings are permanent, and independent on all instants. What I'm saying has nothing to do with this though:
If the the difficulty is constant, your payout per day converges to the expectation of the payout on the first day, which is the same on any pool. The variance is irrelevant. If the difficulty increases, your winning per day does not converge to the expectation on the first day, since the expectation itself changes (goes to 0).
This makes the variance and consequently choosing the pool relevant.


OK I agree that what is rational is one thing, and what people do is another.
I think miners get to experience the variance very quickly though. Probably it often goes like this:
a miner with his new rig joins a small pool because it's good for all. He watches his incomde for a
couple of hours and sees that it is zero. Meanwhile ghash gets a few blocks. He thinks -  well, I could
have already made some coin! Damn. I guess I have to stick to my pool because now we are more likely to find a block! Wait, this is gambler's fallacy.  What I was doing in the past few hours does not influence my  future income. I can just as well switch to ghash now and start earning me some coin!!!
Of course there are also some who quickly get a profit from that 1% pool, but it being a 1% pool, most don't.

yes that's an important consideration and a different argument.
Ultimately I think it would have been easy to make P2Pool dominate the network, and then the variance argument would play in its favour, had it not been for the fact that with P2Pool you need  to maintain a copy of the blockchain.

I wasn't reasoning about the expectation. Only about the variance.
The expectation is the same on any pool, but on a small pool you are more likely to get a value
well below the expectiation - or well above indeed -  which is a gamble. Taking this gamble is not rational.

In other words, continuing the gambling analogy, many would prefer winning 2 with probability 1/2 over winning 100 with probability 1/100, because the former is less risky.
  
Minimizing variance is minimizing risk, and I still maitain that this is rational given that the expectation is the same.

The increasing hashrate is relevant, since had it been stable, in the long run the profit per day from mining on any pool (or even solo) would be the same:  it converges to the expectation. (This is what I referred to as "recovering expectation".)

I didn't get the last point.  



I don't think so. Just ran some numbers, and unless I'm making some very silly mistakes the variance only increases.


It's an example of the tragedy of the commons. Being selfish and letting others solve the problem or sacrificing  one's interest for the sake of a negligible contribution to the greater good.

 I agree though that the variance difference between the largest and second or perhaps even the third largest pool is negligible, so choosing the largest pool is probably mostly ignorance. However,  if 3-4 pools have >50% hashrate this is still hardly a decentralized environment, so choosing between the few largest is hardly relevant. Choosing one of those 1% pools (incl. p2pool) does appear risky though.

I think miners choose the largest pool not because they don't care, but because they want to reduce the variance. Variance is very important when the difficulty is rising fast - if you mine less than expectation in the first two weeks, you may never recover the expectation if the difficulty jumps but your hashrate doesn't.

Thus it is rational  (though selfish) to select the biggest pool.  

Thanks for the answer! What about "native" multisignature addresses (not P2SH)?
From what I found, addmultisigaddress requires n keys where
" Each key is a bitcoin address or hex-encoded public key ". So each of these can be a multisig address
as well?

I read in  this thread that
for m of n  P2SH to be standard  it must have m<= 7 and n <=15.

To get around this, would it be possible to have a P2SH  m of n script where each of the m redeaming addresses is another m' of n' script? 

If such transactions are posible, then I'm pretty sure one can build a tree of 2-of-3 transactions to achieve m of n for any possible  m and n.

here your "employee" is outside Kyrgyzstan. And the ATM is  inside.
For your last step "Family member takes bitcoins and trades for local FIAT" they'd need an ATM that works
the other way around, like I said in my  post.  The currently available ATM may be useful for many things but does nothing to facilitate "sending money home to Kyrgyzstan"

To impact how they transfer money home, the ATM has to work the other way around. Convert BTC into the local currency (or dollars).

I think there was a proposition of "replace with a fee", that is,
if you broadcast a double-spend with a higher fee, other nodes would accept and relay it.
It certainly makes sense for miners to accept such a transaction (and of course discard the previous one).

I've been thinking about the possible use of the public nature of blockchain to mitigate corruption.

Imagine a country where the currency is bitcoin.  The government has one public
address for the country's budget.  All the taxes one pays should be directly traceable to this address.
Then all the outgoing transactions the government has to explain. Each recipient has to sign the explanation
with his key. If he doesn't, the government better explains to the taxpayer why it paid someone not willing to sign for the money.   It is easy (and desireable) to make it possible to make the transactions anonymized from some point. For example, the chief of a police unit signs for the salary fund for the current month, then distributes the money. Each officer signs for his pay, but then he is allowed to use a mixer (his spendings are henceforth private).


Of course not a complete cure for corruption, but it seem this could go a long way to help.

I don't see what this has to do with finite supply or with  bitcoing in general.
It's just people lending each other some currency for an interest, and some trading platforms
facilitating this. FOr example, bitfinex offers the exact  same service for USD accounts.

where are we with respect to this?

I looked at the tor listings recently, and the drug markets appear to be flourishing.
There is a dozen now, SR2.0 is apparently the biggest, but there are 3-4 with a close
volume. What is more, several of them offer multisig escrow, so the market cannot steal
the funds.  That seems really cool.

 I don't know whether any implements hedging against price fluctuations,
like SR did. Anyone knows?

anyway  I can't do anything with my 1000 owl unless I deposit more money at coinprism.
oh well. I wouldn't call it a majour problem, it just prevents me from fooling around with the coins.

the obligatory 0.0001 transaction fee is a bit of a pita for playing around with these colored coins,
which are only 0.000006 each

I think it's rather
Value of colored coin = max {value of IOU, value of underlying BTC}
because you can either  use it either as IOU  or spend the BTC but not both

Also, on coinprism the minimal amount of BTC to creat a coloured coin is 600 satoshi,
which is rounded up from the 540 satoshi dust limit