Greetings, I recently updated my IPhone 3G to the latest OS 4.2.1 and unlocked the device with redsn0w and so forth - and it works beautifully. Prior to this update , I had previously JB the device and had it running on t mobile - but it was always buggy and constantly freezing up on me. As the result of this, I have not activated this Iphone with Tmobile service - as I wanted to see if I could run the IPhone with a free "voip sip" provider and using it in combination with Google voice and boxcar for example. Though since I have added these apps like: Boxcar and a acrobit SIP client, it has been my speculation and question that currently I am not getting instant "push notifications" - which leads me to believe that this is the result of not having service ( is this correct? ) In the contrary , I have read many IPod touch users, having success using their Ipod touch as a Phone and getting instant notifications. Finally, does anyone have any clues or suggestions, on how I can configure this Iphone in this method or if it is doable. Thanks for any advise!!