There is some chaos going on with the price and all exchanges are offering different prices!
The arbitrage method here is as simple as it could be:
1. Buy BTC at
http://btc-e.com2. Sell BTC at
http://thebitcoinexchange.ioThe price difference at the moment is around $50!
Trading between two exchanges can be an advantage only if you can get the bank transactions done quicker (which is highly unlikely). By the time you will change your BTCs the price would be a lot different. Think about the large fee you will have to pay at the exchange to rush your transactions.