Mike's daughter is heading to Europe for a few weeks and he wants a good phone for her to avoid roaming charges. Leo says that for such a short trip, it's probably easier to just get an International Data Roaming plan from their carrier (in this case, T-Mobile) and bring her phone with her.
The other option is to use an unlocked GSM phone and then buy a temporary SIM card from a local vendor. That would give her a European number. But going to different countries, there isn't a master SIM for all of Europe. So the best bet is to go with the international data roaming plan.
EKIT has a regional SIM for up to 10 countries. They'll want to be sure it works in the country she's going to be in, though. She can also get a data only plan there.