I haven't actually had anyone want to play a half dragon in any games I've run, but I've played with people playing Dragonborn. Which is a whole kettle of worms on its own. I mean, Dragonborn. Gee, you look like a dragon. I couldn't possibly guess you were born with some dragon in you. That and dragonborn breasts. It caused a flamewar on the official D&D forums. But that is another crazy topic for another crazy time.
Until the looney strikes again,