rationalskepticism.org

I'm not aware of any state that could send someone to prison for smoking a joint. I think the majority have de-criminalized it, and it's into the double-digits for states that have legalized it. There may be a few leftovers who could technically do it for possessing one, but I highly doubt it would happen to anyone not already on probation these days.
I'm not sticking up for the warped justice system, just saying.