La Tomatina is the world's biggest food fight. It's held every august in Spain. My pal AJ arranged his own Tomatina, Sonoma style, at Gundlach Bundschu winery for his 40th birthday. There were a few rules:
You had to wear white, you had to wear goggles, and you were not allowed to throw whole tomatoes. You had to squish them in your hands before hurling them. (less info)