My junk mail just ends up being kindling for the next trash burn. For those who are just tossing their stuff in the dumpster. I'd highly recommend you reconsider. This is how Identity theft occurs. Get a cheap shredder, and shred the offers.
Of course, I do like Palangi's idea. I could use them to help me clean up the dog's yard. A nice little box of dog poo as a thank you for cluttering up my mailbox with crap.