Hi guys, as the topic says, I'm travelling to the US soon (Thursday), and I'll be there for ~3 weeks. I'm looking to use my iPhone 4 there, the more data the better, don't really care about calls etc. I'm guessing I'll have to buy a prepay sim, or some sort of topup sim. Any suggestions? The AT&T / Verizion websites aren't very clear when it comes to prepay / non contract phone stuff!