Bing Maps Java SDK provides a Java wrapper to Microsoft's Bing Maps API. This allows developers to access the API's methods for searching for points of interest, getting driving directions, matching addresses to the map, and more. This project is currently open for adoption as the creator no longer has time to maintain it.
The most popular API, in terms of mashup count, is far and away the Google Maps API, which accounts for 41% of all mashups. But when it comes to the most popular pair of APIs, Flickr and YouTube mashups are the most common. Not to be outdone, Google Maps joins Flickr in a near second place.
Back in February 2010 we asked Why can't you share photos on Foursquare? We discussed that this could be seen as an oversight or an opportunity for others. However, this question has now been deprecated by Foursquare with the introduction of its add photo API method, which suggests that the previous absence of a method was simply because it wasn't a priority, it was an oversight or the opportunity hasn't been taken up by developers as Foursquare had hoped. In addition to the new add photo method, Foursquare have also introduced API methods which allow comments to be added and deleted from checkins. These methods have already been rolled into the official iPhone and Android apps along with a few 3rd party apps that use the Foursquare API.