Things I did at the movies
1) Maggots, buy a pot or three of bait maggots at your local fishing store and just hurl them in random directions.
when the lights go on people will begin demanding refunds if they find them in their popcorn buckets.
2) Cellayer phone, hide an old phone somewhere in the theater and just keep dialing its number.
3) Tuna, If you go to a theater where you get treated badly, bring a can of tuna and a small knife. slash a small hole in the seat and poke the bits of tuna into the seat. they will probably have to replace the seat.