This resource allows you to enter a city name or zip code, then on the subsequent map, get the mailing address of any point on that map.
The number of ways that various websites use Google maps is really incredible. There are blogs devoted to sharing various applications and "mash-ups," such as Google Maps Mania. Also, if you want to see if anybody has created a particular way of using maps, you can always Google the words "Google maps" and then your topic, like real estate, celebrities, or dog parks. The search doesn't need quotation marks or any other special technique.