Originally Posted by freecia

Piranha Mobile offers both TMobile and AT&T networks on the same prepaid sim, though you do have to change profile via their online portal. It offers US and UK number for the same account.

One thing which irks me about most US MVNO prepaid plans is how the top up credit expires approximately 90 to 180 days and credit/sim can only be kept active with another top up. For a phone which really is rarely used, Piranha's convenience of using it once every 420 days and kept with credit > 1 GBP is hard to beat. The rates per minute aren't the most competitive but I don't need to keep adding credit to avoid expiry. No maintenance fee and it also works in a lot of other countries. Most US prepaid sims do not offer a global roaming feature http://www.piranha-mobile.com/

In addition to Howard Forums, I'd also suggest checking out http://www.prepaidphonenews.com/ which splits their review charts by MVNO and underlying carrier.
http://www.prepaidphonenews.com/2011...ice-plans.html
- See Light users

H20 plus, with $10 top ups every 90 days = 800 minutes/year for $40, as long as you top up before current credit expires.