This is not crafty, per se, but my DD's preschool saved up a whole bunch of them and let the kids use them as large building blocks. The kids made walls that were easy to knock down and put back up. I supposed they could have spray painted them, but they left them as is.
Maybe you could decorate them on the outside and turn them into gifts. You could paint the outside a pretty color and fill them goodies or gifts-in-a-jar type of things. Or you could paint them to say things like, "Vacation fund" or "girls night out fund", drop a little money in there ($1-2) in seed money and give to friends and family as a way to say, "I support your goals" or "I want to spend time with you doing fun stuff."
Another idea with painting them would be to help kids get their rooms organized. My DD is 6 and has tons of little parts. We purchased plastic shoe boxes from the dollar store, but if we had coffee cans (plastic or otherwise) we could have painted the outside and attached a picture of the item that goes inside the can.