This user has not filled out their profile!
A pub crawl (or any kind of tour, really) based on Foursquare. Sign up for the crawl at a web page, then get a notification of the first location. Check in there, and get a notification for the next place...
Working on it at the SF hackathon. Wasn't working, so we have temporarily abandoned it.
FYI, we discovered that someone made the same idea for the 2011 hackathon: sqavenger.herokuapp.com/
This user has no skills!