Going au naturelle in the city needn't be limited to the bath. Started in 2004 by a handful of anti-oil/pro-bike riders to highlight the vulnerability of city cyclists, by 2007 the Naked Bike Ride had amassed more than 1,000 participants — a tally they're hoping to beat this year. If you're not too intimidated, show up in the body-painted buff under the statue of Greek hero Achilles for the 6.2-mile ride, which rolls by Trafalgar Square, Westminster Bridge and Covent Garden.