No need to spend $500+ for a phone if you don't want to - the Google Nexus 4 starts out at $300 and is quite a nice phone. You can also search around for refurbished unlocked GSM phones for good prices.

I'm excited for T-mobile's switch. Not so much specifically for T-mobile's plans and pricing (though they are good), but more generally to hopefully force the other big 3 companies to offer better no contract options and better pricing.

Does anyone know if, with T-mobile's new offerings, I would be able to activate it for a month at a time when I'm back in the States? I'm spending about 2-4 months a year in the US, so I can hardly justify being in a contract or paying every month when I'm overseas. I would definitely throw T-mobile some money their way if I could do this.