Adam Wibler's Pyro is an amazing gadget that looks and acts like something out of a James Bond movie or My Little Pony. It's a wrist-mounded device that shoots fireballs up to 10 feet away from the user. It has 4 chambers, each of which carries a single fireball load.
Pyro has a built-in remote control system. It's possible to activate a unit from up to 30 feet away. So if you have a friend wearing a Pyro unit, you could use the remote control to play mirthful pranks on him.
-via Design Boom
This.
(P.S. 10 feet isn't very far. Can your elves make it shoot farther?)