T-Mobile also has a new prepaid tourist plan $30 USD for 2GB of LTE data, unlimited slow data after that. It is finally catching up to several international carriers who've sold specialized plans to tourists avoiding roaming fees for years! Not the best deal but it does come with a free sim and T-Mobile in-store setup so you won't need to find wifi (which I've had to do to activate some international sim kits) or anything else to get it going.

https://prepaid-phones.t-mobile.com/...l-tourist-plan
http://www.cnet.com/news/t-mobile-to...or-30-dollars/