I wanted to let you know, I just released the full implementation of the paper I sent you a few months ago, Bitcoin v0.1. Details, download and screenshots are at www.bitcoin.org
I think it achieves nearly all the goals you set out to solve in your b-money paper.
The system is entirely decentralized, without any server or trusted parties. The network infrastructure can support a full range of escrow transactions and contracts, but for now the focus is on the basics of money and transactions.
There was a discussion of the design on the Cryptography mailing list. Hal Finney gave a good high-level overview:
One thing I might mention is that in many ways bitcoin is two independent ideas: a way of solving the kinds of problems James lists here, of creating a globally consistent but decentralized database; and then using it for a system similar to Wei Dai’s b-money (which is referenced in the paper) but transaction/coin based rather than account based. Solving the global, massively decentralized database problem is arguably the harder part, as James emphasizes. The use of proof-of-work as a tool for this purpose is a novel idea well worth further review IMO.
Satoshi