And this is something very difficult to do.. i still can not understand why everybody thinks that this is something new.
What you are talking about is called arbitrage. There are several people who use scripts for it, they have bots that compare prices between the various exchanges and make the right trades when the price difference between exchanges is worth it. I can't tell you where you can get those scripts, probably many script sellers will just try to scam you...
This is arbitrage guys! And it can not be done manually unless that you really know in where to look for or how to get the damn job done.
Anyway, just buy one of those scripts and you will be fine.