Is it possible for a HTC Google G1 3G Phone to work (make calls) by inserting a Tmobile prepaid SIM?

I have a Google G1 Phone and a Tmobile prepaid SIM card. Is it possible to insert the SIM card into the Google Phone and the phone automatically can make calls and work? If not, is there any other way?Is it possible for a HTC Google G1 3G Phone to work (make calls) by inserting a Tmobile prepaid SIM?
yes it is but it sorta difficult. INSERT the prepaid tmobile sims card and go to wifi setting and act as if your gonna connect and then block it.....someone else had walkd me through the steps