I've had several people pick me up over the years. I noticed that I had a higher chance of getting a ride if I was wearing something nice, heh.
I try to pick people up when I can, sort of a karma thing to return the favor. Cept usually only if I'm packin. I guess it's kinda sad, but I don't usually take the chance otherwise. It's only gotta be that one time you try to help someone out and it bites you in the ass that completely turns you off to helping anyone else out ever again.
When I was driving back across the country, I picked a guy up in texas and dropped him off on the western side of Arizona. Nice enough old guy, even though he was crazy as a loon! Was muttering about lights in the sky and the government spying on us with satellites and secret military bases and such correlating to markings on the road.
I dropped him off at a gas station, bought him a map, circled where he was, showed him how to get to where he was goin. Had three sleeping bags in the van, so I gave him one.
Sometimes I wonder what ever happened to him.