Interesting idea, unfortunately I tried it tonight by calling the San Francisco area numbers and there was no one on line. According to Google Maps there are few traffic incidents though, will download the iPhone app to see if there are more people there.
Have you been able to use it yourself ?
UPDATED - installed the iPhone App, it's just a "front-end" to help you find the closest community and then it dials-in to the "conference-call", so no more luck getting info, will try again tomorrow.