Nudity is like religion: tolerable in moderation but embarrassing in excess. Combining the two, like members of the aptly named "Fools for Christ" who loved to let it all hang out during Russian winters, is a proof of being out to lunch in a big way. Escorted by wife and toddler and partly concealed by a body-board, I have found swimming in the altogether to be altogether liberating (less so when a topless woman borrowed my surfboard). Anything more seems to be making too much of a testimony out of the testicles.
Philip Carr-Gomm is less judgmental. In A Brief History of Nakedness, he describes the many contexts for being nude, naked, stripped off, in your birthday suit. "You can skydive, bungee-jump, get married, perform stand-up comedy, go clubbing at 'Starkers' disco or fly in the nude." Male dancers bare all in what is known as the "ball scene" of Swan Lake. At a mixed-sex rugby match on a New Zealand beach, the teams play in the buff, interrupted by streakers - who are fully clothed.
More seriously, witches or Wiccans worship when "sky-clad". The Naked Bike Ride protests against "indecent exposure to cars". Lady Godiva rode through Coventry to persuade her husband to lower the townsfolks' crippling taxes; well, she probably didn't but there was a nude horse-ride through Hyde Park to promote a film. People strip to protest against GM crops and, if they are Raëlians, for GM crops. (Raëlians believe Earth was created in a lab by aliens, naked or otherwise.)
People undress for peace, and, when humiliating prisoners in the Abu Ghraib prison, strip other people for war. In Canada radical Christian "spirit-wrestlers" set fire to buildings as a protest against compulsory education. Until Hitler told them to keep their pants on, some Nazis were nudists.
People go naked in public for the right to go naked in public. A strong argument against that right is provided by the photograph of the editor of a naturist magazine on the top of a plinth in Trafalgar Square as part of Antony Gormley's "live artwork". If for you the low point of the excruciating Patch Adams was Robin Williams mooning at his graduation ceremony, avoid the full frontal snap of the real Dr Patch Adams.
Carr-Gomm provides a readable and intriguing survey of this ever-engrossing subject, avoiding the psychobabble one might fear from a former psychotherapist. I won't say that reading this book is the most fun you can have with your clothes on, but it certainly beats risking frostbite by posing on a Swiss glacier with 599 other naked people in a righteous protest against global warming.