US phone US roaming and int'l calls

[Motel75]

I use T-Mobile USA, and the long validity is a big plus. As others have mentioned, you can use a callthrough service - cheapphonecards.com has a couple of cards that don't cost very much to call the UK (Mega Clean Pinless being one), and once you set it up you don't have to enter a PIN any more. It states an expiration of 365 days, but I've been able to use them a long time after this.

You might also consider getting a T-Mobile UMA (Wi-Fi) phone, which allows you to use your US phone from any wireless router you have access to. That's pretty useful if you want to call the US from outside, as there's no roaming available.