So I'm trying to convince my dad to get an iPhone 4, but it all comes down to cost. He lives in Sioux Falls, SD, an area that previously didn't have AT&T service, until a few weeks ago. He used to have Alltel service, until AT&T apparently purchased some of the cell sites out there and now his service is being completely transitioned to AT&T's. His previous bill was around $70, and the closest bill for an iPhone that I could come up with to what he had is about $90 (1500 messaging, 950 minutes, 200MB data). For him, that's a bit expensive. So, I'm trying to bring the cost down by looking for alternatives. Who knows, maybe he could talk less, but I've looked at Google Voice and Textfree as options. The only problem is, I'm pretty sure he doesn't want multiple phone numbers. I'm fairly familiar with Textfree, but what about Google Voice? Does he have to have another phone number? Does it cost anything? I'm looking for some advice. Any help is appreciated. Thanks!