Medical Marijuana
I've never done any illegal substances in my life. I've smoked a couple cigarrettes (yuck) and had my share of alcohol and that's it. I think that if somebody wants to toke up and get stoned, that's their own business. I've never heard of a violent crime occuring because someone was high on pot, and yet we have people getting in bar fights and killing one another because they're drunk off their ass.
To my knowledge, there's never been much of a problem with driving while stoned. I'm not even sure it affects your ability to drive the way alcohol does.
Pot should be legalized, provided that there are laws made about it that reflect those made for alcohol and smoking. Driving while stoned should land you a hefty fine, etc etc. If someone feels like they NEED this crap to feel better, why not let them have it? Tax the sale of it just like you do with cigs and be done with it.