Originally Posted by
mrcamp
As mentioned, Tmobile is your best bet in this situation. Once you topup with the $100, you can just topup with the minumum of $10 yearly to keep it going. I have had a tmobile sim for the past 6 years that I use as a backup, and this is how I have kept it going.
One note: if AT&T merges with T-Mobile, expect this to go away.
What I would do is sign up for Google Voice and get a US number. Then whenever you come over, sign up for any old prepaid service with the minimum top-up (usually $10) and forward your GV number to it. Saves you from having to waste the initial $100 on airtime, and you don't have to worry about when T-Mobile's prepaid plans go away. You don't care what your prepaid cell number is and will probably end up with a different one every time, but no one will ever know it because you will only give them your GV number.