I was hoping to save this tidbit for when I actually received a super-cool "gift" from one of my many, many NPN 3x5 card mailings, but I have yet to receive Jack for my efforts and thought I would share the wealth. Yes, you read that correctly - I got nothing, so I'm sharing it with everyone.
Anyway, if you are not familiar with the term "NPN," it means "No Purchase Necessary." (collective "aaahhhsss" of recognition all around). Basically, you send a 3x5 card with your contact info to the right place(s), and wait for your prize(s) to arrive. Or, in my case, you just wait.
There is a site I visit every so often: http://npnsportscards.com/. This site gives you the addresses of places to send your stacks of 3x5 cards. It gets updated whenever the author discovers a new NPN opportunity.
Since my luck has yet to pan out on it, I thought I'd see if anyone else had better fortune. Good luck!