If you have a paper supplier in your area (like Xpedx.. graphic designers and print shops use these type stores to order paper for professional printing jobs), you can go in and basically take as many samples from their open containers as you want. They have tons of crack n peel and colored sticker papers, etc. They also come in 8.5 x 11 sheets which = big stickers.
Or if it's not set up like that, tell them you are doing a project for school/college and need some samples of crack n peel because you're going to be ordering a large quantity and want to make sure it works with your printer first.
I would just look in the phone book under "paper suppliers" "paper retailers" "paper manufacturers" something like that. Xpedx is the best, if they're in your area check them out. You can definitely get a ton of free crap just by saying you're a design student and you want samples for a school project.
Hope that helps.