Topps, the venerable granddaddy of baseball cards, puts expired and signed contracts up for sale in it's web store. These are true 1/1's (for those of you that are into that sort of thing).
When a player signs a contract with Topps it gives the company the rights to use the players name and image in promotion of the company. In turn, Topps shoots over cash. It's really not a bad deal for both parties but I assume that Topps come out on top in the end. Anyway, these contracts do have expiration dates and when these dates hit the contracts are null and void. That's when Topps them up for sale for collector nerds like you and me.
Anyway, I just thought I would share. Here's a link to those contracts at Topps. Even if you don't buy one head over to take a look, they are all pretty interesting.