I posted about this in the Apple section a while back as a way to get real-time info about traffic. Thought I would post it here as well as it could be a very useful means of sharing real-time information about not only traffic, but also hotspots as they flare up, police blockages, etc. Have a look at Waze. It will locate you via GPS and the you can post alerts, even including photos of the point of interest if you like, using your GPRS/EDGE data connection. It's free, runs on iPhone, Android, Windows Mobile, and Symbian phones. and if enough of us are using it, it could serve as a network for keeping up on what's happening.

http://world.waze.com/download/

Nifty. Thanks for the link.