Hold mouse up to ear like a cell phone and yell "I can't hear you!!! You're going to have to speak louder!"

Play Pac Man and state to person next to you, "These new games are incredible!"

Practice 'spinning mouse mat on index finger' globe trotter routine.

Put your monitor's contrast and brightness on full. With wide open eyes yell "It's going to implode!"

Tell the cashier you wish to redeem your free 1000 hours and hand him a bag full of collected AOL promo CD's.