So you're moving from AT&T to Verizon. What should you do with your old iPhone? You could hand it down to someone who is already under contract with AT&T. Or use it as an iPod touch, without a voice or data plan. You could also try to sell it on eBay or Craigslist. But if you just want some quick money, there are several firms waiting to turn your phone into cash. Many of these firms guarantee that they wipe the data on your device, so that might be worth some peace of mind. They also typically offer volume deals for businesses.
