The Bing Maps PHP SDK allows developers to integrate the ability to display and interact with Bing Maps into PHP web applications. This library is provided for free under the GNU General Public License v2.0.
Another API can be added to the list of "Google APIs That Are No More." The Google Latitude service, including the Latitude API, will be shut down on August 9, 2013. Google Latitude is a geolocation sharing service that allows users to find friends and family on a map as well as share their current location with others they choose.
There are any number of questions that can be answered by Wikipedia, but you can add "where am I?" to the list. Given any latitude/longitude coordinates, the WikiLocation API will find you corresponding Wikipedia articles to tell you about your surroundings.