via a my home wireless network? I heard about something like this with T-Mobile at Home..... My problem is that I live in a little valley and when my friends come over with their iPhones, they get no signal. AT&T's coverage misses me, but it's there 1 door down..... So, I can't get an iphone if I won't be able to receive and make calls on ATT. Is there some way - not via Skype or VOIP.