I was just about to cancel my T-Mobile Service that I have 7 months left on (have been with 17 months) to get a iPhone 3GS -- but have read a lot of complaints about AT&T's rates and service. Have also read a lot of times 3GS speeds are not that high on AT&T's overloaded network and that you're often essentially paying extra for nothing. What is a going rate on an unlocked 16GB Iphone and how are they obtained? Am not really familiar with the unlocking thing--but want to be sure I research all my options thoroughly before moving over. Also am kind of unclear on what T-Mobile's rate plan would be if I was on an iPhone. Have just had it dealing with these 2nd-best phones and want to move over to iPhone one way or the other. Advice appreciated--Thanks!