I discovered the joy that is podswap  yesterday in our live Tuesday geeksugar chat and I'm really impressed with the site. It functions on one of my favorite premises: One person's trash is another person's treasure. Apparently, the site offers an upgrade path for people who want the “latest and greatest” iPod available - and who doesn't love a place that gives you the in with the hottest new gadgets? If you're not afraid of used gadgets (I know some of you are on the fence with this) you can get functional, and guaranteed iPods, or you can sell them your broken or malfunctioning iPod in almost any condition.
The eBay Alternative:
While you can sell your own iPods via online auctions, the “Podswap Advantage” eliminates all the hassles of listing, collecting payment, shipping, and dealing with post-sale issues.
Good parts get used, bad parts get recycled via earth-friendly methods. Podswaps says it avoids an aggravated toss into the landfill or an Ebay auction with an unhappy ending.
If you're looking to get an old 1st or 2nd generation iPod for its Vintage Geek  factor, this isn't the place, but the site does have a good selection of 3rd plus  generation iPods.