A bearer-backed market basket currency (rather, the ability for anyone to create a digital bearer token currency as a service; billions of currencies, and realtime exchanges to determine prices and exchange currencies at transaction time) is my #1 idea for a project. Unfortunately not really a path to profitability, so I'll do something more mundane first.

I'm glad I ducked out of e-gold (we were building a digital bearer currency backed by e-gold, in partnership with them) before the e-gold prosecutions started. Kind of sobering talking to the lawyers 10 years later and seeing what pain I missed.