See your foursquare check-ins on Bing Maps or Google Maps.
Xbox Live, TV, Bing Maps And SteveB At UW [Demo Videos]
Videos of the demos shown at Steve Ballmer’s Cloud webcast at Univeristy of Washington.
[Update] Foursquare Using Both Bing Maps & Google Maps
Foursquare is using Bing Maps for their Facebook integration whereas are making use of Google Maps on their website.