As long as it is an unlocked
GSM phone, it should work. Two weeks ago I bought an unlocked RAZR V3 on eBay. It had been a Cingular phone, but it worked with the T-Mobile ToGo
SIM card just fine. I was also able to modify the phone so that it now has all the T-Mobile programming on it, instead of the Cingular stuff. (Look in the Motorola forum on this site
and here for links and further info how to do this.)