In California, it's pretty much legal now to buy, sell, grow, and smoke pot, provided you've got the proper documentation from a doctor, which is pretty easy to get. This article from the New Yorker details the industry that's sprung up around this legalization, filled with people who, you get the feeling, really like smoking pot for recreational and not medical reasons.
The counties of California were allowed to amend the state guidelines, and the result was a patchwork of rules and regulations. Upstate in Humboldt County, the heartland of high-grade marijuana farming in California, the district attorney, Paul Gallegos, decided that a resident could grow up to ninety-nine plants at a time, in a space of a hundred square feet or less, on behalf of a qualified patient. The limited legal protections afforded to pot growers and dispensary owners have turned marijuana cultivation and distribution in California into a classic "gray area" business, like gambling or strip clubs, which are tolerated or not, to varying degrees, depending on where you live and on how aggressive your local sheriff is feeling that afternoon. This summer, Jerry Brown, the state's attorney general, plans to release a more consistent set of regulations on medical marijuana, but it is not clear that California's judges will uphold his effort. In May, the state Court of Appeal, in Los Angeles, ruled that Senate Bill 420's cap on the amount of marijuana a patient could possess was unconstitutional, because voters had not approved the limits.
Senate Bill 420! The LAPD and DEA have taken the stance that federal law takes precedence over state law and are routinely busting people for growing, selling, and possession. It'll be interesting to see what happens in the future here.