Like learning to use chopsticks, skateboarding takes patience, dedication, and a particularly dexterous set of toes. Show off how flexible your feet are with today's Groupon: for $39, you get a 10-session unlimited pass at Inner Space Skatepark (an $80 value).

Designed by boarders, Inner Space Skatepark's 7,000-square-foot indoor skate park is a safe sanctuary where skaters can practice kick flips, develop aerials, or break in a brand-new deck. With a 10-session unlimited skating pass, board masters can hit the ramps and handrails and test the limits of their grip tape for as long as they like. Borrow a helmet ($3) and a board ($5) or bring along personal gear won from street races against gangs of robots to protect body parts as you glide across ramps that have hosted Nike-sponsorship events and gilded the famed wheels of celebrities such as Lil Wayne. Inner Space is open seven days a week, so neither rain nor pesky sunshine can stand in the way of a proper day gleaming the cube. Humanoids younger than 18 years are required to protect their underage heads with a helmet, but those 18 and older just need to wear a full set of noninvisible clothes. Skaters can cruise the pipes unhindered all day, however they cannot leave the park and return to resume a session of skating.