A Really Cool Cannon

I saw this video on YouTube, but my mom found it again here. I really wanted to make a big air cannon but soon found out that those big trash cans are not cheap. It took a bit of thinking, but I found a way to make a little air cannon. This is a picture of the one I made.

Materials List:
Rubber band
Styrofoam Cup
Plastic Sandwich Bag

Here's how I made mine:
First, take a styrofoam cup and cut a hole in the bottom that's about 1" around.
Next you might want someone to help you. Take a sandwich bag and cut off the zipping part. Have your helper hold the plastic bag over the top of the cup while you put a rubber band around it. To fire, flick the sandwich bag. Enjoy! (P.S. You can help your mother dust with it!)