The OpenStreetMap library for Android supports the API functionalities that include overlays of markers and tracks. Java users might benefit from additional API uses such as reading and writing operations of the OpenStreetMap database.
Last week Flickr announced a great set of enhancements to their service: geotagging of photos on a map. Once again they've done a nice job in the interface by making it really, really easy. Drag-n-drop them on the map and you're done.
Foursquare, a location data company best known for its City Guide, has relaunched its Places database and has released a new Places Enterprise API to accompany the update. These announcements are intended to bolster the company’s point-of-interest data offerings and expand data availability.