I have an iPhone 3GS with a plan, but I have a question for unlocking if I wanted to do it in the future. After my two years are up and I'm at college, I've been thinking about getting an unlocked iPhone and just using it on a prepaid T-Mobile plan or something. I have a few questions.. 1. Does using an unlocked iPhone 3GS with T-Mobile fully work or are there any limitations? I know calls and everything work, but I believe 3G doesn't work because of different frequencies or something? Please let me know. 2. Now that we have Google Voice, can't I just get a T-Mobile pre-paid card with NO minutes, NO texts, and JUST unlimited data? That way, I can use Google Voice (which requires internet and a phone number, but not a plan). Am I right? Can I just get a unlimited data plan w/ no mins and texts and just have all my calls forwarded to my real phone number for free? 3. If 2 is a feasible option, are there any T-Mobile pre-paid plans out that have only unlimited data. If there is an option with unlimited data and like 20 low minutes, I'd be interested in the price on that as well. I know that in two years the same plans may not exist, but I would still like to know what's available now. Thanks a lot.