Hitchhiking is probably not as dangerous as we give it credit for, but it's seriously out of vogue. Unless the car we're getting into is a registered taxi, most folks want nothing to do with it.
RidePost is trying to change all that. Working in a similar fashion to home-sharing service Airbnb (another in the "let's welcome strangers into our private spaces" school of online start-up), RidePost allows people who need a lift from one town to another to coordinate with people who are making that journey and have a spare seat in their car. Drivers can charge the hitchhikers if they want, or else can just do it out of the generosity of their own heart.
RidePost is still in beta at the moment meaning that it only deals with Kerouac's U.S., but if you are planning a trip there at any point in the future you could do worse than meeting some locals and seeing the countryside from a front seat.