When you're vacationing on a beach, nothing beats an underwater camera; but watertight cases are pricey and disposables have lousy quality. Lucky for you, the editors of PopSci have come up with an easy workaround using something there's probably already plenty of in your suitcase (hint: not socks). That's right, thanks to the magic of unlubricated condoms, you too can transform your point-and-shoot into an waterproof wonder. The set-up is easy enough, but as John and Doug demonstrate, it really does help to have a partner lend a hand.

You never know when the level of festiveness in your home might suddenly become critically, even dangerously low. Thankfully, one vigilant soul has put such concerns to rest by creating the Emergency Party Button, a DIY system that with one press transforms a seemingly ordinary apartment into something resembling Rick James’s rumpus room.

Ever wanted your own motorized off-road skateboard? Listen in on this week's podcast as staff photographer and DIYer extraordinaire John B. Carnett relays the story of his latest exploit. It's a special all things How 2.0 edition as Carnett sits down with host Chuck Cage and editor Doug Cantor to discuss explosions, motors, hacked TiVos and more.

Tetris is one of the all-time classic video games, but it’s best suited to people with a lot of free time on their hands. Apparently, though, maneuvering those little polygons around a video screen still wasn’t enough of a time suck for Swiss artist Guillaume Reymond. So, he set to work on a real-life version of the game with people in place of pixels.

Sean Captain’s extensive guide last week to next year's nationwide digital TV conversion featured some interesting comments from the vice president of Centris, a company that recently published a study suggesting the upcoming switchover to digital-only television broadcasts may leave millions of people across the country without a TV signal. The National Telecommunications and Information Administration is offering people who have an analog TV a $40 coupon to put toward a converter box. Unfortunately, Centris VP Barry E. Goodstadt says, in certain pockets of the country, using a converter box still won’t give you a signal if you don’t have a powerful-enough antenna.

If you thought Doug Cantor’s disposable cam-belt buckle project was a little crazy, then get a load of the Amazing Chrome Calculator Belt Buckle from BWild (aka Village Street Wear). Why would you want/need a calculator belt buckle? Good question. According to the BWild marketing copy, this buckle is "great for cheating." "Why get caught with the wrong answer," they ask, when you could "never again struggle with simple equations or complex formulas." Oh, and it’s "great for accountants," too.

Hmm, isn’t fiddling with a chrome-finish calculator hanging from your waist bound to call you out as a cheater? And if an accountant starts fingering his belt buckle, it might be time to look for a new accountant. Good thing you had your disposable cam-belt buckle to record that zipper-cipherin' incident. —Dave Prochnow

(Image: Bwild.com)

The “Laser Finger,” the Palo Alto (Cal.) High School team’s head-mounted remote control intended for use by quadriplegics

This week is the Lemelson-MIT InvenTeams Odyssey, an annual program showcasing some of the coolest inventions you'll see anywhere. The twist is that all the brilliant inventors behind them are still in high school. Teams of students received grants of up to $10,000 last fall to develop a prototype intended to solve a problem of their choosing.  Check out some of the kids showing off the fruits of their labor above and in our slideshow—just in case you needed a reminder of how you wasted four years of your life.—Doug Cantor

Cellphone cameras are kind of an afterthought in the U.S., fun for snapping off a picture of Great Uncle Harold blowing out the candles at his 93rd birthday party, or occasionally handy for a few seconds of grainy Zapruder-esque amateur news video. But that’s hardly the case in Japan, where cell cameras are like an extra appendage used for a host of applications not available in the West.

PopSci is all about the children—we staunchly believe, as the sage Whitney Houston instructed us, that we should teach them well and let them lead the way. Unless, of course, they’re the kind of kids who tend to wander off while you’re on vacation.

Fortunately, we’ve got that base covered too. In the April issue, How 2.0 featured a “Hardware Trick of the Month” showing how to recover a lost USB drive by equipping it with a piece of software that displays a custom message requesting its return whenever it's plugged into a computer. It turns out one prescient reader took the trick a step further, attaching drives to lanyards and hanging them around the necks of his young children while the family was at Disneyland. Sure enough, his three-year-old son disappeared, only to be found by a Good Samaritan and brought to the Happiest Security Facility on Earth. Security personnel then plugged in the USB drive, got the boy’s name and his parents’ contact information, and he was returned quickly and safely—an ending befitting, well, a Disney movie. Check out the full story from our friends at Daily Cup of Tech, who wrote the original script for the USB trick. —Doug Cantor

Link - Have Your Lost USB Drive Ask For Help