When there's only one other person in the elevator, tap them on the shoulder and then pretend it wasn't you.
Push the buttons and pretend they give you a shock. Smile, and go back for more.
Ask if you can push the button for other people, but push the wrong ones.
Call the Psychic Hotline from your cell phone and ask if they know what floor you're on.
Hold the doors open and say you're waiting for your friend. After awhile, let the doors close and say, "Hi Greg. How's your day been?"
Move your desk in to the elevator and whenever someone gets on, ask if they have an appointment.
Lay down a Twister mat and ask people if they'd like to play.
Ask, "Did you feel that?"
Stand really close to someone, sniffing them occasionally.
Call out, "group hug!", then enforce it.
Grimace painfully while smacking your forehead and muttering "Shut up,all of you, just shut up!"
Crack open your briefcase or purse, and while peering inside, ask,"Got enough air in there?"
Wear a puppet on your hand and use it to talk to the other passengers.
Make explosion noises when anyone presses a button.
Stare, grinning at another passenger for a while, and then announce, "I have new socks on."