Cinco de Mayo is a pretty big deal in the Bay Area, particularly in San Jose, where there is an annual parade, and a Cinco de Mayo Festival (which ran all weekend and concludes today). Basically, it's mostly about celebrating Mexican heritage and culture. The annual Mariachi contest and dancing exhibitions are quite popular.
As with past years, I'll have a few margaritas and walk around checking out the exhibits and bands with friends. It's a good opportunity to build intercultural community bonds and to better understand people of Mexican heritage, whom make up a sizeable percentage of the population here.
ADG