I don't drink coffee so I don't have any real-life experience w/ these cans... So everything I say may not really work!
I saw a cool idea in Seventeen or YM magazine last year (not that I read these magazines anymore, I swear!!). They painted a coffee can on the outside & inside & then mounted it on a wall w/ a drill/screwdriver thingy, & used it to hold CDs. I don't know if they're really big enough for that, but other wise, they could hold some kind of doll from your childhood, or they could hold anything small, I guess. Then they painted the lids & made a mobile that was kind of cool.
Then there's an idea from http://www.thriftdeluxe.com/
about alternative framing methods, where they use tin cans as picture frames. You could also mount the tin on the wall like the above idea, & put a photo on the lid to make a sticky-out 3-D frame... Does that make any sense??
Okay, fresh out of ideas. Good luck!