Look, no pants! Thousands of sparsely-clad cyclists take to the streets of Britain and beyond for some clothes-free freewheeling. For those involved, there's more to biking in the buff than mere exhibitionism; it's also a protest against oil dependency and "a symbol of the vulnerability of the cyclist in traffic". Bond with your two-wheeler like never before, and arrive early if you fancy a bit of pre-pedalling body painting; it could prove a life saver when you find yourself unexpectedly trundling past your boss.
• London, Cardiff, Sheffield, Sat; Brighton, Sun; worldnakedbikeride.org/uk