Here's a nifty use of Google's collaborative mapping. Cascade Bicycle
Club has launched a website where people can share information about
potential bicycling hazards - reporting crashes, thefts, and hazards.
You can check out a new route in advance, or keep an eye out for
possible bad news that hasn't yet happened to you on your current
routes.

You can set a default location, and they say it's supposed to be
useful "anywhere in the world," so it sounds as if Oly bike riders
could just start using it to share local information...

http://www.bikewise.org/