Listen, you’ve been able to trade in your unwanted video games at Amazon for, I don’t know, forever, but they’ve just changed the game: now you can use Amazon Trade-In to swap your books, media, cell phones, and other assorted tech with relatively little pain.

It’s super easy to make the most of Amazon Trade-In–just check to make sure your items are eligible, then print your label and ship them off, and Amazon credit is deposited to your account upon receipt. Amazon is hardly the first place to offer this service, but they’ve got two huge points in their favor with this gig. First, where are you most likely to head to buy new stuff? Exactly. And second, check out the right sidebar on the Trade-In page–they’ve conveniently listed eligible items you’ve recently purchased, complete with the trade-in value. (Not that you necessarily need to trade-in something that’s two weeks old. But still.)

For reference: Yesterday their cell phone trade-in value of the day was the 8G iPhone 3Gs going for up to $163. Not bad if you have your eye on the new 4G iPhone in White.

If ever you needed a little bit of justification towards getting the latest and greatest version–“I can recover half the price selling my old one!“–there you go. -Mir

Check out the Trade-In Beta at Amazon.