Developers have created over 35,000 Google Maps mashups, marrying the Google mapping platform with external data sources to create all sorts of interactive maps where users can find information on apartments for rent, bike routes, hotels, gas station fuel prices, parking garage fares, and so on.
My Maps has a graphical, drag-and-drop interface that lets users create a map, add placemarks to it, as well as draw lines and shapes. Users can also add notes, photos, audio clips and videos to placemarks.
Users can choose to make their maps public or visible only to friends. The Google guys have already taken it to the next level with a map and photo collage of their campus. Coming soon: Live, constantly updated maps of every security camera in America–perhaps with video feeds.