On July 11, 2009 there was a Guinness World Record Set for the Largest Skinny Dip.
Click here for the AANR Page about the Skinny Dip

• The Official count for Gunnison Beach was 808 skinny dippers, Way to go! We had the largest turnout of any group in the Nation!!
• The national count: "On July 11, 2009, history was made when 13,648 people throughout North America celebrated the joys of skinny-dipping, and in doing so, set the first world record for this marvelous experience." - aanr.com

NBC News had a webpage (and the accompanying video that aired Saturday Evening - July 11, 2009) - Unfortunaley it is no longer available on-line