Associated Press: Robert Gilliland didn’t think much about carpooling until gas prices got out of control. Now, he’s happy to trade his motoring freedom for $120 in weekly savings. Gilliland found one rider through the classifieds Web site Craigslist and another using the carpool-matching service eRideShare.com. Thousands of commuters like him have turned to the Internet to arrange shared rides as average gas prices hover around $4 a gallon. Each day, Gilliland picks up Brian McKenzie near his …