Hello,

sometimes it seems possible to buy BTC at one exchange and sell it immediatetely at another one, making some arbitrage profit.
Of course, we have to take differences in the currency exchange rates into consideration, too.
Therefore I have launched a site showing those arbitrage opportunities:

http://nyse-group.de/bitcoin-arbitrage

What do you think about it?
Comments/suggestions are appreciated!
Have fun,
Roman.