It's a good idea, but if I may say so, you're thinking much too small. What you need to be thinking about is learning how to write a program that will automate the entire process for you 24/7. Or just how much a respectable coder who knows how not to get things like passwords intercepted would charge you for the one he wrote himself.I'd be amazed if there aren't hundreds or even thousands of little personal ones processing away at this very second. The problem, of course, is getting the money OUT of the exchange you sell at. BitInstant is quick, but their cut is so large the difference in price at the exchanges has to be pretty big to make any profit at all. I'm sure a lot of people made a killing doing it at first though.