Hubmaps

The Pittsburgh City Paper wrote a great article on
Maphub. It's an excellent usage of the Google maps API. It's specific to Pittsburgh, where each "hub" provides specific information on a particular topic. Much of the site is currently dedicated to bicycling in the city - which is very much needed. You can map bike racks, bike repair shops, etc. Best part is it's based on contributed information. I highly recommend checking out the bike crash hub, where you can map all of the bike-car accidents in the city - as well as organize by date. This is a perfect opportunity for influencing or informing public policy though technology.