We here at TUAW aren't quite sure how great a deal this is, but just in case you want to take advantage, Toys R Us is apparently offering trade-ins on old iPods. From October 17 to the 23rd, the toy chain will take old iPods (no model is specified, but I'd assume older won't get you as much money) at the customer counter, paying out up to $100 in gift cards, just to buy a new version of the device.
Unfortunately, the deal's not available online, and not all stores are participating in the promotion, so the old "Your mileage may vary" adage very much applies here. Definitely call before you go, and if you do bring an iPod in, you probably shouldn't expect to get any extra money for that full catalog of Aerosmith CDs you've got saved on there.
Who knows, though -- if your household happens to have a few old nanos sitting in a drawer somewhere and you want a quick and easy way to turn them into a new device, this might be worth trying out. If it works for you, be sure to let us know.