Backbeach and I have an ongoing debate about this. Surprised he hasn't dropped in the first salvo... :^)
I'm for decriminalization all the way. Dozens of legal things more dangerous than smoke. I don't even smoke. (Anymore)

Probably wouldn't start either if it was legal, though I'd indulge in an occasional cookie.
How many violent crimes, suicides, etc.. related to it every year? Damn near none as far as I know. I'd much rather deal with someone on smoke than half in the bag drinking, though I doubt alchohol abuse would decrease if Marijuana was legal.