It's still there, I'll post a link when the forum gets unbusy.
EDIT: Ah, here we are!
http://boards.cannabis.com/activism/167741-ideas.html

And I got some slogan ideas. Two from marijuana.com
Something like I support legalisation as the main theme of posters and then....
"Because I need protection from murderers and rapists more than I need protection from junkies and stoners."
"Because there are no gangs fighting over whiskey territories"

And my own I thought of a while ago and just remembered....
"It's not a health issue, it's a wealth issue."