Thanks for all the support in this thread Mike.

I'll delve briefly into the political debate myself:

Once there's a significant number of Bitcoin businesses using tax evasion as their competitive edge, the authorities are going to get nasty pretty quick. Where do people see this going? So far I've really only seen 2 responses:

• Go black-market. Sure, you can. But if at least part of the Bitcoin market is legitimate, Bitcoin can have a much greater influence and utility.
• Some form of tainting. If we're really lucky this might be something like what Mike's proposed in the other thread. I suspect what we'll end up with will be much more draconian though. You can still have your black-market at the same time as this.

EDIT: This sounds pessimistic, but I'm actually really enthusiastic about Bitcoin's long-term prospects, and of course have some coins myself. I just think it's good to think about the bigger problems when there's actually a lot of stuff you can do to combat it.