I once thought about a way to "legalize" pot:
You must register as a smoker, you get a credit card type thing, and it is rationed. The rationing is to keep someone from buying pot for others than themselves. sell it in 15 "joint" boxes like cigarettes, limit 1 person to 30 "joints" a month, basically 1 a day (each "joint" approximately the size of a Camel straight). To register you must be 21 and have no criminal record. Get busted for a crime (even a misdemeanor), lose pot license for 10 years.
Sell the pot for $30-$50 a box, thats $60-$100 for a months supply for 1 person. I'd bet it is a TON cheaper to make, distribute, and it would take in a windfall of money.