Solo:

1) Make race car noises when anyone gets on or off

2) Grimace painfully while smacking your forehead and muttering: "Shut up, dammit, all of you just shut UP!"

3) Offer name tags to everyone getting on the elevator. Wear yours upside-down

4) Do Tai Chi exercises

5) Tell a stupid story about something random like your trip to Mars to no one in particular

6) Frown and mutter "gotta go, gotta go" then sigh and say "oops!"

7) (If its crowded) Say "Thank you all for joining me here today

8) Say "I have been expecting you" when someone gets on

9) Lean against the button panel

10) Bring a chair along

11) Start brushing off invisible bugs from your arms, screaming "Aaughh! Get them off!"

12) As the elevator is going up, jump violently up and down, shouting "Down! I said down, dammit!"

13) Have a twister box with you and say "Anyone up for a game of twister?" and begin setting it up

14) Walk in, and start reciting a shopping list in monotone

15) Stand right in front of the doors when waiting to get on

16) Ask, "Did you feel that?" 

17) Hit every floor button, and at each floor get out and say, "Nope, this ain't the right one." Get back on and ride to the next floor. Repeat. 

18) Sit in the corner and meditate. "Ohm."

19) Get a vote from the entire elevator about some completely pointless issue.

20) Ask if you can push the button for other people, but push the wrong ones.

21) Sing one part of a song over and over again in monotone loud enough to be heard by everyone in the elevator (Make it an annoying one)

22) When the other people in the elevator leave, yell "SHARON!"

23) Greet everyone getting on the elevator with a warm handshake and ask them to call you a different name every time

24) Wear a puppet on your hand and talk to other passengers "through" it

25)  While the doors are opening, hurriedly whisper, "Hide it. quick!" then whistle innocently

With a friend:

1) Pretend to be having a full out teen drama fight

2) Get your friend to say "I am so glad you got out of that mental hospital this morning" and you say "I ATE MY WAY THROUGH THE DOORS!" in a creepy accent

3) have a fake spider (larger or medium) (or real ;) ).. your friend says "Those shoes are ugly" then you tell the person beside you "Hold my Spider imma bout to kick this aliens butt!"

4) Walk in with your friend wearing trench coats and dark glasses and say to her (or him) "I can't believe we haven't found the unsub)