The Google Maps team has announced the beta launch of Local Context. With Local Context, site and app owners can integrate the typical Google Map experience into their properties, but that experience is amplified with rich, local information (e.g. shops, restaurants, etc.).
When Google first launched its location-sharing service, Latitude, developers were left wondering how to access their users' data. Now, over a year later, we finally have a Latitude API. But we also have a number of other similar services that have better traction and are arguably more fully featured.
When it comes to map mashups there's no doubt that Google Maps leads the way. On ProgrammableWeb we list 1,964 Google Maps mashups, almost four times as many as any other API. This popularity makes utilities built on top of Google Maps especially interesting, such as this contextual menu control, which pops up a menu when the user right clicks.