Make a tin can knitter. (Something on my list of things I think it would be fun to do with my kids)
Make Luminaries.Simply put water in the can and freeze it and then draw a design on a piece of paper and lay it on the can and use a hammer and nail and punch a design. You freeze the water in it so the can doesn't dent when you are hammering. Paint it if you desire. (here are some 4th of July ones)
The base for a centerpiece
Make a hobo stove for camping. (I have long planned to try this but never have.)
Make Boston Brown Bread (you use tin cans for the "pan")
Kids craft: Tin can lamb.
Or let them make a Turkey.
Make Fabric covered vases
A kitchen utensil holder (Similar idea as the vases just much bigger!)
Make tin can stilts!
Tin Can dollhouse furniture. (and I can imagine some that are much simpler to make than where the link goes.)
Tin can Elephant purse (super cute!)
Punch holes in the end and then pour water in it to softly water your seedlings.
Set melons (in your garden) up on a tin can to ripen with out rotting where they touch the ground.
Tin can hanging planters.
Tin can lid matching game. If you have the type of can opener that unseals rather than cuts (so there are no sharp edges!) you can put stickers on one side
Tin can Dog Robot
What else can you add to the list?
For more frugal ideas please visit Life as MOM