Facebook Timeline, the new profile design launching soon on Facebook, makes broad use of the Bing Maps API. Similarly, the Facebook Places feature also incorporated Bing, but now both maps use a different, more simplified style.
Our API directory now includes 146 location APIs. The newest is the LongLatToLocation API. The most popular, in terms of mashups, is the foursquare API. We list 86 foursquare mashups. Below you'll find some more stats from the directory, including the entire list of location APIs.