Hello, I want to give the G2 to my sister and buy the HTC sensation for myself. Because my sister is a very heavy texter and she doesn't use the phone for anything else beside talking and texting. I called Tmobile and the rep told me that he can't activate the G2 on my sister account (which is on the same family account with me). He said to be using the G2, the account must have data plan. However, i discovered that all android phones (or maybe most of them) have the option to use only 2G networks. So my question is, is it possible for me to just activate the option and plug my sister's sim card into the phone? Is it safe to do that? cause we don't want to receive a huge data bills on my sister account just for using the phone. Any suggestion ?