I currently have t-mobile as my service, but with no data plan. If I were to purchase a google nexus S from Bestbuy (just the phone without the 2yr contract or data plan upgrade) would I be able to just put in my simcard and It will work just I wouldnt have internet (except when in a wifi zone)??

Or would t-mobile enforce some type of activation or something where they would force me to upgrade to a data plan??