The annual Santa Skivvies Run is becoming one of the most anticipated holiday events in San Francisco. The "festive romp" through the city begins at UN Plaza and follows Market Street to the historic Castro. Hundreds of people turned out in the rain this year to run for the SF AIDS Foundation to raise awareness and fight HIV/AIDS. The Santa runs take place in several cities around the US that all benefit LGBT causes. Don't miss the upcoming Polar Bear Skate on New Year's Day in San Francisco.