Boycott California wine.
I think California wine is the best thing to boycott, because it is available in all 50 states, it is something that is easy to replace with something else such as French, Italian, Australian, and South American wine.

Boycotting tourism to California is great, but if you arn't planning a vacation to California one can't join in on the boycott.

Boycotting hollywood movies is great also, but most films are not filmed in California anymore (thanks to the unions).

So if you are living in the East coast, Mid west, South east and all points inbetween partake in the boycott by passing over California wine the next time you are buying a bottle.