I have researched this for a while, and have found little tidbits of information on the subject, but I have never really found a simple guide to using an iPhone on T-Mobile. I am currently on T-Mobile and would love to use an iPhone 3GS. Where do I start? Do I need a special SIM card or can I use my current one? For service can I just use the $10 a month internet plan in addition to my call and text plan? What would be the most up-to-date way to unlock a 4.0 iOS iPhone and successfully get in working on T-Mobile? Basically guys, I just need a starting point on how to do this. Your help would be greatly appreciated.