I've never done it, and don't think I ever would. Certainly not with my face visible! I don't like having my picture taken at all, let alone with nudity involved!
If I tried it, I'd probably be so nervous that I wouldn't even be able to get an erection. I'm shy with strangers in real life, and I think knowing that countless strangers might see a video of me would make me unbelievably nervous.
I did actually have phone sex once, back in 1996 (the only reason I know the year is because it was just before I moved away from California after getting out of the Navy). I lived with a friend at the time, and she had AOL, and told me about the chat rooms. I mostly visited the opera discussion chat room, but the only other guys there were always gay, and they would send provocative messages. Eventually one of the guys I hit it off with via chat suggested a phone conversation, which turned into phone sex. He had a sexy bass-baritone voice. Never did it again, though, because it was a bit awkward for me due to shyness.