Sell Girl Scout cookies.

Shave.

Crack open your briefcase or purse, and while peering inside ask: 'Got enough air in there?'

Offer name tags to everyone getting on the elevator.

Stand silent and motionless in the corner, facing the wall, without getting off.

When arriving at your floor, grunt and strain to yank the doors open, then act embarrassed when they open by themselves.

On the highest floor, hold the door open and demand that it stay open until you hear the penny you dropped down the shaft go 'plink' at the bottom.

Exercise.

Stare, grinning, at another passenger for a while, and then announce: 'I've got new socks on!'

Moan from the back, 'Oh, not now, damn motion sickness!'

Meow occasionally.