I have been advising my restaurant customers to offer customers a perk if they check in on Facebook Places or Foursquare and it has been paying off for them as it keeps driving their name out to these mediums.
Now Foursquare is being used for events and happenings around town and those events have also been experiencing and increase in foot traffic.
http://bits.blogs.nytimes.com/2011/08/18/foursquare-lets-users-check-in-to-events/
