I think this idea has been worked on by a lot of people too. Way back in Hackday India 2007 a group of guys worked on an app called Socialrouting which was hos

I think this idea has been worked on by a lot of people too. Way back in Hackday India 2007 a group of guys worked on an app called Socialrouting which was hosted at socialrouting.com (it's currently down). It allowed users to mark and view routes with respect to landmarks and also allow people to update traffic in a particular area via an SMS to the SocialRouting twitter account, which was then transferred to the map on the site. I was impressed by the way Pradeep (one of the dev) gave a talk at a Barcamp about their mashup. And now, I guess that was the idea that morphed into Mapunity http://www.mapunity.in http://www.mapunity.in which they are currently working on. It provides live traffic data for a few cities in India. These guys provide services to govt organisations. P.S: I used their Traffic API in Hackday India 2009 :D thats how I know about them :)