If you can actually log into mtgox with Tor you are lucky. They constantly update the Tor IP's because that is how they have been hacked in the past - they disable login through known Tor addresses, so unless you get a pretty new one you can't get on Mtgox at all.Use a tumbler. It's 0.5%, and well worth it. This mixes your coins in with a bunch of other transactions so it is virtually impossible to trace the BTC chain.It should go: Bank (ayee! use an anon credit card or something here if you can) --> E-currency --> MtGox ---> wallet --> tumbler --> SR, then reversed on the way out (if you are selling). Tumbling is key. There are new exchanges out that will let you use Tor to connect to them (Tradehill, cavertex (for canadians)), so you can be anon the whole way through if you fund with a pre-paid credit gift card.