Go into a public bathroom stall, and sing LET IT GO! LET IT GO! CAN'T HOLD IT BACK ANYMORE!!! while plopping fruits and other items in the toilet.
Push on the eraser of a lead pencil until the lead is really long, press on it one more time and hold it, then push it down on your arm and start crying/screaming. The lead will go back in the pencil, but it looks like you just gave yourself a shot!!!! :D
Bring a mat (and friends) and attempt to hold yoga class in an elevator, a store, or the mall-.
When you and your family will go out write "Help, they kidnapped me" on a piece of paper and go at the back of your car and hold the paper up make sure that it can be seen outside.
Have someone hold something for you and walk away. if they try to give it back to you object.
Go out in public, hold up a piece of fruit, say "you are my best friend" and see what happens.
Sit in a public area and pretend to read a book, but hold the book upside down and see how many people notice.
Have a better idea for this list? Send it on in!