Even if you missed this morning's free Civic Center simulcast of Barack Obama's inauguration, you can still join the celebration tonight at Electric Works. Staying true to the public-service-minded spirit of the new administration, door proceeds from this Inaugural Ball benefit the San Francisco Food Bank. As befits a presidential swearing-in, formal attire is suggested. If you're coming straight from work, no worries: with changing rooms and a lending library of borrowed finery available, there's no excuse not to dress to impress.