Bay to Breakers San Francisco, CA

This isn't just one of the largest and most colorful foot races in the world; it's a festival of events that benefits a variety of charities. The 12K race starts promptly at 8a each year on the third Sunday in May at the intersection of Howard and Spear Streets in downtown's Financial District. More than 100,000 people, runners included, attend the race each year. Many dress in wild costumes. You never know what you might see, but be on the lookout for giant-sized, mobile Katamari spheres being rolled across the city by drunken revelers. The weekend ends with a street festival, Footstock, that features live music. Please visit the website for more information.