That was exactly what we tried a year ago (mobile-based ridesharing). It did not work for us because: 1) Hard to get traction due to the classic chicken-and-e

That was exactly what we tried a year ago (mobile-based ridesharing). It did not work for us because: 1) Hard to get traction due to the classic chicken-and-egg problem: Ride sharers do not sign-up due to the lack of riders, and riders do not sign-up due to the lack of sharers. 2) People do not trust on anonymous riders. We hoped to solve this issue by introducing a social network where we would prioritize the matches by degrees of separation. But that didn't work due to #1 3) The large majority of the population enjoy their privacy in their own car and do not have a motivation to share the ride (perhaps when gas prices get higher) 4) For those who are motivated enough to share a ride, there are plenty of options available out there: Craigslist, employer's bulletin board, in additional to local authorities (ex: 511.org and casual car pooling in Bay Area) Seems like this one (web based, not mobile) got some traction: http://www.ridester.com/ http://www.ridester.com/