1. Take the soda bottle and cut off the top part of it.
2. Wrap the balloon around the top of the soda bottle and secure it on with a rubber band.
3. Fill the balloon with bb'(s) and pull it back.
4. Release and watch the bb's go flying.
Check out my YouTube channel for this and other tutorials: http://www.youtube.com/user/vistigioful/videos?view=0&flow=grid&sort=da.