Is it right, if I am a parent, to offer my child one joint and only one joint of marijuana so they can experiment in a controlled environment?

This is somewhat inspired by last night's House; the parents gave their kid a joint in the past (not a factor in the show or diagnosis) and my parents, when I was in high school (1998-99ish), said they were OK with me smoking weed at home or with friends, just so long as I got home safe and nobody did really bad drugs like cocaine, heroin, etc.

I am a total victim of DARE. I won't touch the stuff myself for fear of health concerns, but I disagree with the War on Drugs as it pertains to casual use of marijuana. There's worse things out there and we could use the boost in tax revenue. I want my kids to understand that as far as I'm concerned, when they're teenagers, they're basically young adults, and if they want to make the choice to break the law, they should know both sides, good and bad. They need to realize that if they risk their future, they should have a safe shot at it from me, their father, and not from some stranger or dealer with ill will in mind.

Opinions? This is just a thought that popped into my brain. (I don't have kids, don't worry)