Originally Posted by UAVirgin
FYI on the Virgin Mobile prepaid card (purchased in the UK). I just checked the fine print and you can't roam with the card in the US unless you go for the montly billing plan.
The T-Mobile UK prepaid works pretty well too in roaming. The downside with the UK mobile pre-paid SIMs is that the rates are in pounds, a currency which remains stronger and more stable vis-a-vis the dollar more than the euro. A non-pound denomination will likely be cheaper per minute than a pound sterling-denominated one.