Earlier quoted context omitted.
For various definitions of "world-changing" (i.e. one disruptive enough), the US is the worst possible place to do it. A fair example being how fucked all the bitcoin startups are going to be once the market is big enough for FinCEN to care about... or e-gold if you want a historical one. The US is fine and dandy... if you don't mind not having privacy, and keep your "world-changing" ideas within the lines of what th…
I'm curious: what country do you think would be better than the US for starting a bitcoin startup?
The key IMO to all of this is separating out software development from server operations from financially backing a currency from applications of the system from auditors from users. Banks suck at software development; developers suck at finance. By separating the concerns, you can do regulatory arbitrage as well as focus on your strengths. (this isn't my idea; I think Ian Grigg of Systemics came up with it in the early 1990s, if not earlier). Fully separate arms-length entities, different people, not the e-gold "offshore, really" approach. You could create a fully anonymous bearer blinded token infrastructure as software, and then have servers for it, where some of the currencies were entirely non-financial and thus non-regulated (distributed locking mechanism for distributed software systems, resource allocation, anti-spam credibility systems, game currencies), and others which were financial currencies issued by real, established financial institutions with KYC (a dollar currency, shares, futures, ...). Same software, so the developers have no legal risks themselves.
Luxembourg also works, if you have $3-5mm or so to meet the requirements to issue (at least, that's what it would have cost in the late 1990s when I last looked; you need some connections, but they come with having money and hiring people from the industry). Switzerland and possibly Liechtenstein may work. I'd skip dodgy ee or south pacific places (e.g. Vanuatu, Narau) since correspondent banking relationships would be trivial to sever.
If you were totally focused on gambling ("gaming"), some crown colonies (IoM, Gibraltar) might work, or Panama.
You could do it in the USA if you met KYC and also treated it as a commodities trading system, regulated under CFTC. You can become a CFTC exchange (like Chicago) for $5-10mm. I'd probably actually do the operations for that in Chicago just to be totally known to all the local regulators, although NYC or SF would also be possible.
The thing I absolutely wouldn't do is try to run a payment system which is at all anonymous in the US, and if I did a payment system in the US, it would meet all KYC and MTB requirements. That puts your capitalization required at a few million dollars more than otherwise, but it's not a big deal.