@satoshi: then it was not very wise of you to not register that one as well. if you didn't invent this exceedlingy smart system i'd even say 'foolish'.
i don't think that this is that trivial. if they have a trademark on the name in conjunction with online financial transactions, they will sue any commercial entity using bitcoin, once bitcoin gets larger.
the only corporation i could find using that name is
Bitcoin Ltd
Computer Software Development
34 Arlington Road
Camden Town
London NW1 7HU
this could be their telephone number, though it seems too long. possibly two separate numbers. 024 8189 2502 - 07593 528009
Is there someone in London who could pay them a visit? Having the .com domain as well as the .org would be great.
if it is not them, a telephone call or letter to
http://en.wikipedia.org/wiki/Domains_by_Proxy should do the trick.