Well I guess if it were easy everyone would be doing it.

I think there is a fair bit of scope for it in the bitcoin markets

just a quick look at bitcoin charts reveals thUSD @ 13.41 and Britcoin @ 9.76 XE says USD->GBP @ 1.62

9.76 x 1.62 = 15.8 so the Britcoin market is effectively trading a couple of $ above the thUSD right now. Even allowing for currency conversion costs you could make instant profit on that.

Anyone got any clue how to set up a US account from the UK?