I've done it twice. Once was this random guy that came up to me in the night. Looking back, I think he was probably trying to get away from somebody, because he kept looking over his shoulder, but by that point he was in my car. He was fine as far as how he behaved to me, he was just very jittery and nervous. I took him to his destination not too far away and dropped him off.
The other time, was the random, elderly woman who came up to me in a parking lot, and asked for a ride. I agreed, and she offered to repay me by giving me a blowjob. I politely declined, because while I have nothing against older women, and in fact find them very attractive, this lady was not in any way, appealing. She actually got offended that I didn't want a blowjob from her, and gave me attitude for the rest of the ride. I took her to a house, and I'm pretty sure it was a drug dealer, given where we were, and by the fact that the place was being staked out by a police car. The cop started following me after I dropped her off, probably to run my plates, since I was a new person at that address.