Also used as a toy on a
rainy day. If you have siblings or parents that don't mind being annoyed, you can have fun with these cans.
What I used to do was sneak up behind my sister as she was talking to her friends on AIM or listening to whatever pop star was famous at the time...and I'd spray in one of her ears. It didn't matter which. Her head would jerk to the side the can was on. (If you replayed the moment in your head in slow-mo, it's pretty damn hilarious ... *back and to the left*...anyways). After her head twitched, her entire body would hop in the air about an inch of the chair and a short and high squeaky scream would come out of her mouth.
She would be extremely pissed but I had fun doing it.
Stuff like that is fun to do when the compressed air doesn't have any other use.