Drupal - Tools for Google maps

QuikMaps - Allows site visitors to annotate Google maps using an interface reminiscent of simple paint or image editing applications. After annotating a map, users may save the maps for later editing, share the map by way of a URL, or post the map to any website. All without knowing a lick of JavaScript.

Mologogo is a free service that will track you and your friends using GPS-enabled mobile phones.