Ah, summertime. The kids are out of school, everyone's on vacation, and there's no better time to get out from under your laptop — not yet! — and get a little physical exertion into your daily routine. Sure, you can throw the ball around with the wee ones or reconnect with that pickup basketball league you've been putting off. Why not try something different? Beyond the major sports we all know, there's a growing subculture of amateur sports enthusiasts who are not only reviving old sports but creating new ones. Here are some of our favorite outdoor activities that may have escaped your radar, and let us know what else we may have missed. Above: Octopush Also known as underwater hockey, octopush's origins date back to 1950s England and the Southsea Sub-Aqua Club. The creator was Alan Blake, who taught himself to dive in 1949 with no equipment. Just five years later, he had fleshed out his new sport, which is essentially hockey played along the bottom of a swimming pool. The game is six-on-six, with players — outfitted with snorkels and fins — trying to stick a weighted puck (3 pounds for adults) into the opposing team's 10-foot-wide goal area. The obvious downside here is that it's not conducive to spectating, but there is an official ruling entity — the World Aquachallenge Association — if you want to learn more about organizing your own matches. Just don't forget to hold your breath. http://www.youtube.com/embed/CqI7yLUixH4 Photo via Wikimedia Commons

Kronum Outside of constructing the custom goals, kronum only requires a circular field roughly 70 yards across, a lot of stamina, and your head on a constant swivel. There are players coming out at you from all angles, and where you are on the field determines how many points you score, if you throw the ball in either the goal mouth or one of the five crown "rings" lining the top of each one. Kronum is fast, challenging and the perfect summer sport for those looking to throw a dash of rugby into their competitive soccer. http://www.youtube.com/embed/etm54u7MA3A

Hantis Perfect for any driveway, the creators of Hantis bill this as the "first extreme table sport with no boundaries." It's simple to play, as scoring is based on varying combos of the ball (better known as a "loach") striking players, the tables and even your external surroundings (called X-Factors by hantis players). Overhead costs are low — you only need four tables of equal dimensions and a tennis or handball — and games can go quickly once everyone knows the rules. A younger, hipper cousin of pingpong, Hantis can be enjoyed by amateur athletes of all stripes. http://www.youtube.com/embed/nlvfQ5js90o And if you need an easy-to-follow refresher, here's a handy quickstart guide: Photo: Hantis.net

Segway Polo Yes, it's probably the geekiest sport imaginable — polo played atop roving Segways? — and it's endorsed by the Silicon Valley nerd elite from Sunnyvale to San Bruno. But Segway polo is a serious outdoor activity. Since 2004, Segway polo has evolved into a fully respected sport with its own league, a governing body and a rule book. Oh, and it's got the star power of Apple co-founder Steve Wozniak, cornerstone of the Silicon Valley Aftershocks (pictured above, second from right) who'll be hosting the 2011 Woz Cup later this month in Folsom, California. Then again, if all you're looking for is a little quiet time out on the links, this golf bag-carrying Segway will cost you a trifling $8,000, though we're unsure whether the geek factor here is higher or lower than Segway polo. Photo: pheelmore/Flickr/CC

Quidditch After 10 years, the cinematic conclusion to the Harry Potter franchise finally hits on July 15 with Harry Potter and the Death Hallows, Part 2. So why not a rousing game of real-life Quidditch to celebrate? No, you don't actually get to fly around on brooms, but don't let that stop you from at least trying the sport once. Thousands of people come to New York every fall for the Quidditch World Cup, so maybe you've got the skills to grab that Snitch (whatever that means). Photo: aidanmorgan/Flickr/CC

Road Tennis Long known as the quasi-official sport of Barbados' inner-city neighborhoods, road tennis requires only a stretch of pavement, a table-tennis net, paddles and a handball. Not recommended for those with chronic back problems, road tennis has a rich history going back some 80 years, and there are clubs all around the island where you can find veterans and up-and-comers alike. If pingpong has you bored, this is something that'll more than fill that void in your sporting regimen. Image: Professional Road Tennis Association

Shallow Diving This is only for experts, got that? But even the most experienced shallow diver in the world — Darren Taylor, aka Professor Splash — got his start somewhere down low. The trick here is to splash dive from as high a point as you can into a pool of water. Taylor, who has set 14 world records in all, from various platforms and heights, is diving these days from 36 feet up into a kiddie pool measuring 12 inches in height. It's all in the swan dive posture, and that's the only reason Taylor is still alive today. Let me repeat: You can get seriously hurt doing this. But with enough experience, maybe even Professor Splash will one day have some competition for his as-yet-unchallenged tenure.

Tough Mudder This isn't so much a sport as it is a Heart of Darkness–like descent into stamina-stretching madness. Organizers go out of their way to say this is not a race, and one look at any of the courses makes it easy to see why. The next event will be Tough Mudder Colorado on June 25 and 26, and it measures 8 miles in length. Estimated time of completion? Two hours, 30 minutes. That's because you have to snake your way through a military-style obstacle course that starts out at 8,100 feet above sea level, goes as high as 11,440 feet, and boasts a total elevation change of 4,250 feet. There are several more taking place across the United States before the end of the year, so give it a chance — if you think you've got what it takes. http://www.youtube.com/embed/8jjvVEovZVY Photo: jrogich/Flickr/CC

Circle-Rules Football It's the most fun you can have outside with a giant yoga ball — and that includes going to yoga class. Two teams coming at the same goal, trying to score with a ginormous sphere that's been known to bounce uncontrollably and without reason. Originally developed five years ago by Greg Manley, a theater student at New York University, circle-rules football requires little overhead to get started. Your biggest problem will be deciding when you've finally had enough for one day. http://www.youtube.com/embed/1iQZZs_MZZo Photo: Courtesy Sasha Arutyunova