Back in August, Wired contributor Evan Ratliff vanished. Before disappearing, he issued a challenge: whoever found him would win $5,000. He purposely left a few obscure digital breadcrumbs to make the challenge winnable within five weeks, and then got lost.

Yesterday, the challenge was won by the makers of Knight-funded software NewsCloud, a Facebook application for creating social engagement around news. Using a mix of high-tech digital forensics and old-fashioned footwork, Jeff Reifman located Ratliff in New Orleans and conspired with the proprietors of a joint called Naked Pizza to catch him there.

You can read the full account of the sting operation at the NewsCloud blog, and more about the contest on Wired's Vanish blog.

Update - More on NewsCloud: A Slashdot post and hundreds of tweets later, I asked Jeff Reifman a little bit more about NewsCloud, the software he put to unconventional use to help locate Evan Ratliff. NewsCloud's potential as a way to engage younger folks with the news was recently studied in two pilot projects targeting 16-to-25-year-olds, in partnership with Grist.org and the University of Minnesota.

"What we found," Jeff said, "was that the design of the Facebook news application was great at improving daily news habits of young people in the 16-to-25 age range. We found that people started returning every day to get a sense of what's going on."

You can explore the NewsCloud app on Facebook at NewsCloud.com. And you can read more detailed findings from the study on the NewsCloud blog.