Pick your nose, hold out your finger and ask if anyone's hungry.

Hold out your purse/breifcase/backpack to everyone as they enter the elevator and say, "Trick or treat?" in February.

Burp really loud and add, "Wow, who know humans would be so hard to digest?"

Pick one person and insist you know them, say, "Remember me? Yes, you do! It's me!" until they get off the elevator.

Ask someone to help you apply your prescription cream.

Point to someone and yell, "You're the guy I saw on the news! You're the guy the police are looking for!" preferably when the elevator is full.

Scratch your head furiously and say, "The doctor said lice can jump but I don't believe it!"

Start playing the harmonica or kazoo- this works best if you don't know how to play the harmonica or the kazoo.