May 17-In a city where people reserve space in their closets for costumes, it's hard to imagine a time when one San Franciscan actually had to wear a disguise just to run in its yearly bay-to-ocean fun run. After all, Bay to Breakers participants are famous for putting on everything from regular running attire to outlandish costumes, and sometimes even nothing at all. But on March 10, 1940, that's what was done by Barbara J. Burke, who posed as a man to participate.