Popcorn salute
When at a theatre, purchase an extra-large popcorn and enjoy your movie. DO NOT eat the popcorn past the half-way mark. When your movie is finished, proceed to enter a movie that is in progress. Walk to the center lane infront of everyone and scream "POPCORN SALUTE!". Lob the popcorn over the back of your head so it hits the ceiling and explodes over everyone in the crowd. Run.

Also, if you havent finished your soda, dump it in prior to saluting your popcorn for added effect.
That popcorn salute at the end of Narnia II left those virgin nerds covered in sodacorn.