Tony Hawk, of skateboarding fame, put together an Easter Egg hunt for anyone and everyone across the globe on Sunday. Looks like he and his helpers stashed about 50 boards, and then Tweeted one clue per board. A sample clue:
The hunters found them and then Tweeted back a photo of themselves with their loot.
Very cool to see Twitter used this way. 140 characters doesn't seem like much to work with as far as developing a clue, but it worked.
There was limited press beforehand (from what I can tell) so it must have been a cool treat for people that follow him on Twitter. Definitely a great way to increase your following.
Creating more sophisticated clues on Twitter (sequential clues, right/wrong answers) might be difficult, but a one-mission hunt like an Easter Egg hunt is a great application