Is anyone upgraded their G1 phone to Android 2.1 to take advantage of Free unlimited wifi calling w/Sipdroid & Google Voice? I'm on 2.1 on my MyTouch 3G slide and the Sipdroid through PBXes using the Google Voice # is slick. Not using any minutes on my plan, I can set the phone to airplane mode and make calls. If I could get this done on the G1, then I could drop the unlimited package I have. I'm not interested in TMobile's wifi setup, that just uses minutes.