Sprint uses different technology/frequency bands than T-Mo. T-Mobile uses SIM cards too. You still need a sprint phone. Either sell the Galaxy and buy a compatible phone from Sprint, or keep it and go with a MVNO (=prepaid provider) that uses T-Mobile's network. Simple Mobile is one option for you. Here's a huge list of the rest-
http://en.wikipedia.org/wiki/List_of_United_States_mobile_virtual_network_operators
Full disclosure...I'm pretty ignorant when it comes to the cell phone world. My current situation is I'm on a Sprint plan with a dumb phone with my wife. Recently a friend gave me her Samsung Galaxy SIII (TMobile was the carrier) and it is unlocked for international travel. What can I do with this thing? I would like to get a prepaid plan to give it a try, so what's the best out there? Can I go with any plan since it's unlocked or do I need to stick with certain providers?
Not planning to drop Sprint until I feel confident this is the way to go.
Thank you in advance for helpful replies.

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