Craigslist RideShare
You click first on your city and then click the "rideshare" link. This will take you to a page where people post when they either (a) have a ride to provide or (b) are in need of such. The terms of the ride will also be listed (i.e. estimated cost of drive and current price of fuel). You will be able to contact them through the Craigslist email link at the top of the posting.