Something that i know for a fact works is the sites that say free ipod and that companies sibling sites http://www.wired.com/news/mac/0,2125,64614,00.html
http://www.wired.com/news/mac/0,2125,64614,00.html

I actually know some people who do it, its a good way to get free stuff if you dont mind having some junk mail... i certainly dont, i get 80000000 a week anyways!

I would do it but i dont have a credit card.... will when i do though, they just require the credit card for 18 guarantee