Zimride is a rideshare service for campuses, workplaces, or to go to  events. Zimride works with organizations, universities etc to create local networks, but there is also a public zimride as well.  Its free and easy, just sign up. It integrates with  facebook and twitter too. We have Zimride now at my university – you login with you university email, input your route and times, see on a map who is traveling your area and can easily contact them about ridesharing!