Maybe you've seen the webads for FreeiPods.com and their deal for getting a free iPod or a $250 iTunes store credit. Engadget thought that the deal was maybe to good to be true and did a little sleuthing:
The company rep we spoke to insisted that this thing was for real and that they had already given away about 400 iPods to people. To get it to work you actually have to sign up for one of their sponsors’ offers (like the Columbia House DVD club, the GM credit card, AOL for Broadband, etc.) and also get five other people to also take them up on one of their offers.
Even if you've got 5 friends lined up, do read the comments on the Engadget post first. A least a few people there were burned.