So I was talking to 1147's mentor (Karen Sanko) last week about what their team has been up to and she stated that they reconfigured their robot by adding a pnuematic launcher to their arm to launch T-shirts to the crowds at football games. What a coincidence!! We had the same thought as well!! Our CANONBOT has a 4" barrel, about 5 feet long and operates up to 100 psi. We decided to use larger air tanks than the usual ones used by FIRST. At one point it launched 4 water balloons surrounded by 1/2 gallon of water (to prevent premature rupture) about 50 yards. We'll get it out to a football game in a few weeks and launch t-shirts, hot dogs, foam balls, small children, etc...
here's a link to our CANONBOT in action
So who else has had the same idea, and how did it turn out?