Hyundai is running this Mash+Seek contest where they pick 16 people, split them in four groups, and then have the contestants locate the three other people in their teams. The only lead is a quarter of a face, although Hyundai is promising more tips. "The first team of four to find one another wins a new Elantra each."
This is a very cool way to do "consumer-generated content" because guess what? The challenge is not only about locating someone, it is also about making yourself visible, somehow. Blogs? Postings on Craigslist? Google AdWords? I'd do a typical chain letter asking everyone to forward it on.