I'd be down for that, it sounds like a fun project in an interesting domain and I was actually thinking about what building one would entail as I've been reading though the comments here.
Business processes. The code is dead simple. A few hundred lines of order matching. The real meat is handling all the business processes, clearing transfers, etc.
and finding a legally safe location to put a business like that.
Way to suck the fun out of it :) -- I know, I just think a bitcoin exchange is an interesting concept, the kind of thing I would enjoy knowing my code was running in and got a little caught up bikeshedding in my mind how I'd secure a target like that.
You know what's really fun? Chilling on a beach somewhere while girls in grass skirts bring you drinks with umbrellas in them.
For that I'll put my ego aside and do a few weeks of boring work. and yeah, I was fantasizing about neat-o technology problems too. I'd love to build an order matching system. Then I got to thinking about the market size, and taking a cut of each transaction.
and finding a legally safe location to put a business like that.