Google has just announced a new service integrated with Google Maps. It's Street View. With it you can go to San Francisco and and move in the streets watch buildings cars. Ooohhhhh. You've to check it.
How about Maplets?? It's a gadget-like for Google desktop. You can write your own APIs and refer to some places. For example you can make a mapplet referring to places you've captured some videos in. Check the last link, you'll create your hello world mapplet ;)