Originally Posted by
ScottC
it'll possibly be from Virgin Mobile or Cricket - neither of which operate on GSM (the system used in Europe)

what's that got to to with 3G?
To the original poster: it's not clear if your friend is intending to use their US connection in Europe (REALLY expensive rates) or buy a
selection of European SIM
s to work with their device. As ScottC says the device is probably locked to the US provider, so I agree it probably won't work.