This week two prepaid phone carriers, Virgin Mobile and Cricket Wireless, announced they'll begin selling iPhones this month. Although you'll pay much more for the phone up front, the monthly service fees can be considerably less than traditional carriers. The folks at PC world compiled a handy chart that shows a savings of $300-500 over a two-year period. Of course, there are some down sides. Both Virgin and Cricket seem to have smaller coverage areas than AT&T or Verizon. Plus, we don't know whether they'll have the next iPhone when it's released. I'd wager that sales of a new iPhone will be mostly restricted to AT&T, Verizon, and Sprint at the outset, which could eliminate most early adopters. Still, all other things equal, it'd be nice to save a few hundred bucks on service!