Me and several of my friends have been talking about forming a pro-decriminalization (or legalization, I suppose) group locally. If we succeed and more of these groups pop up, you'll start to see the majority's views changing.
join norml and set up a a norml headquarters in your town.... stick with the big groups that are working their asses off to make a difference instead of making a group that'll fade away in a couple months, years... who knows.... im not saying that it will flop.... im just saying you'll have a lot more support joining a larger organization such as norml
