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.
ForWhereIAm is a service that offers real-time, short-lived and localised information. Businesses use it as a place to post information they want to share with their customers, and users can visit the site to get information on deals and announcements that are relevant to their specific location. The ForWhereIAm API makes some of this data available to third-party developers.
Foursquare, the leading location-based social tool, announced a major new initiative last week to expand its location database to include cross-references to corresponding venue listings from other services. As characterized in the announcement post on the company blog, the goal is to make Foursquare the missing "Rosetta Stone for location, allowing you to link information about a real-world place from one database to any other." Now it's not just about using Foursquare, but connecting it to other services.