In the last Wired Magazine, Evan Ratliff wrote a great article about disappearing in the digital age. Part of the article was a contest: Ratliff would attempt to disappear for a month — you find him, you get $5000. His credit card transactions and IP addresses and other such stuff would be posted to a blog, where you could then analyze them and try to track the guy down (with $3000 going to Evan if he wasn’t found).
Just a few days before the 30 days were up, Ratliff was caught. Some folks at Newscloud managed to track down what city he was heading to, and notified some folks at New Orleans that he was going to be in town who subsequently, with a little competition with some other folks in town, managed to track the guy down, take his picture, give the codeword, and win the contest.
The whole blog and all its past entries are an entertaining read, especially the big clue that everybody missed that gave his itinerary pretty clearly.