Senior Panks?

Here's a great one, but it requires a lot of patience to see the results:

Get a tin whistle and some bird food (bread crumbs or popcorn will work). Go out to the middle of the football field every day and blow the whistle and distribute the food. Keep doing this. You'll condition the birds like Pavlov's dogs to associate the whistle with food. During the next football game (obviously you'll need to do this late summer early fall to see during next years football games, but you can do it for other current outdoor sports as well) sit back and watch as the birds descend everytime the ref blows his whistle. No one will know what to do!