Walk into an elevator full of strangers and say, “You’re probably all wondering why I’ve gathered you here today…”
Order a pizza for delivery, walk to the pizza place, and get a free ride home from the pizza delivery guy.
Tape clear saran wrap around your friend’s doorway. See if they fall for the prank and walk into the saran wrap or notice and become confused by its presence.
Go to any store that sells wrapping paper and challenge other customers to a duel with the gift-wrap tubes.