Wikis meet Google Maps
Here's a wonderful idea. Mash Google Maps with a wiki, and you get collaborative location documentation.
Here's Vancouver: http://www.wikimapia.org/#y=49280000&x=-123130000&z=11&l=0&m=a
Here's Vancouver: http://www.wikimapia.org/#y=49280000&x=-123130000&z=11&l=0&m=a