Amazon has added a host of electronic devices -- including iOS devices -- to its trade-in program. The Electronics Trade-In program is currently in beta and allows users to mail in their old, unwanted devices in exchange for Amazon gift card credits. Devices must be in working order and good cosmetic condition. A third-party merchant, not Amazon, is actually the one buying the used devices.
The prices are actually more generous than I thought they'd be. I sold an original 4 GB iPhone on Craigslist a while back and had trouble getting US$75 for it. Amazon's trade-in program currently offers up to $69 for the same iPhone. A sampling of other iOS device trade-in prices includes up to $114 for iPod classics, $235 for first-gen 16 GB Wi-Fi iPads and $162 for an 8 GB iPhone 3GS. That's definitely way more than you'll get if you let your old iPhone rattle around in a desk drawer after upgrading to a new one.