[lambda]

> What is left is keeping track what everyone has put in, and what they have taken out.

And that's exactly what Bitcoin is; a secure digital ledger. It's a way to securely and globally record "person A has 10 BTC, gave person B 5BTC, then person B gave persone C 3 BTC" in a way that doesn't allow person A to simultanously have given those same 5 BTC to person D (who, given the anonymity of the internet, may also be person A).

That's all Bitcoin does; it provides a secure way to record such transactions without having a trusted third party who must trust to increment and decrement the right accounts in the right way.

[lifeisstillgood]

So is that not an impressive solution - if Alice wants to move 100 USD to France and Bob wants to move 100 USD out of France (let's say both want to buy a new textbook) then one could envisage a peer to peer money transfer system.

A site allows bob and Alice to find each other, agree a shared amount to transfer, agree to which end point they will onwards transfers (hmmm this might be the breakdown point) and then record that in the block chain

I think oddly there is still an enormous amount of trust involved - trust that Alice will complete the final important step of giving the money to Bobs silver haired grandmother or whatever

[Natanael_L]

You can actually achieve the same thing with Coinjoin if all involved parties agree. Instead of a bunch of individual transactions, they collectively generate and sign one.