I'm very green to all this and have only had an iPhone about 1 month. I bought a used 3GS and went to a local phone shop that unlocked and jailbroke it. I think the guy said he used Spirit and there is a Cydia icon on the phone. That is all I know. For $10 I figured it was't worth my time to mess with it to do it myself. I put in my T-Mobile sim card and it works fine but the Edge data is on the slow side. I'm wondering now if there is a benefit to upgrade to iOS4? I've read complaints of sluggishness by 3G users after the upgrade. Wondering if there is really much point to update my 3GS or just leave good enough alone? BTW, I read something about only subscribing to the T-zone service for a few dollars a month and that there is a hack to get unlimited data with that. Anyone have a link with more info on that T-zones hack?