me too...i had try to pwn my 3G iphone and after everythings was done,there was no network found.can't make call.anyones knows how to fix the issuse.

tribal, make sure you unchecked the activate box. I had the 'no service' icon appear as well, but try turning the 3G off and try making a call. After a couple tries, it made a call and I got service bars too. Once that happens, you can turn 3G back on.
The reason I turned 3G off is that I don't really get any 3G service in my room, so it makes it easier for the phone to switch on Edge.
This method worked for me...

Guys, I have a similar problem: Got 3g iphone in France and unlocked from Orange. Worked fine for last 3 months. tried to pwnage and now everything works but the radio. no signal, no provider name... no phone. tried to restore using itunes but get errors after the restore completes and the phone gets stuck in iTunes-USB mode. Please help!!!
-Hisham