I've used Foursquare to check into everything from grocery stores to a launch complex, but until last Friday I had not employed that location-based service to check into a household object.

That's when I stopped by the offices of iStrategyLabs, a Washington social-media marketing firm, opened the Foursquare app — revised this morning to make it easier to get recommondations for nearby places — and checked into iSL's "Social Cooler" instead of the company's Dupont Circle address. (Trivia: ABC News host George Stephanopolous lived there years ago, and his mail still sometimes shows up.)

And then I waited for the lid of this cooler, tricked out with a laser-cut version of iSL's logo, to open in response to my check-in. And waited. Technology demos are like that sometimes.

But maybe five minutes later, the check-in was picked up by an Amazon-hosted app monitoring Foursquare's servers, which in turn sent a command to the Arduino logic board in the cooler to run small servos to unlock and open the lid.

In earlier tests, the cooler had been stocked with cold beers; on Friday afternoon, it only contained LED-illuminated plastic ice cubes.

ANALYSIS: Don't Fear Foursquare

There's a long history of connecting everyday devices to the Internet. Online graybeards may recall such pioneering efforts as Cygnus Support's Christmas tree, which in 1993 allowed users to see which of its lights and musical bells were on or off, then, in later years, vote on the tree's illumination.

The ever-cheaper costs of connectivity and computing have since given rise to the concept of an "Internet of Things," in which crazy numbers of devices will gain their own access and ability to respond to other online gadgets.

With iSL's Social Machines project, however, the idea is to ensure that not just anybody online can interact with a gadget.

DNEWS VIDEO: Gadgets and Gizmos

"About a year ago, we literally got bored with social media," said iSL chief executive Peter Corbett. Then they had a thought: "Can we take this action and turn it into an action in the physical world?" And, they thought, what if you also required friends to do something together to yield that action?

That last angle sets Social Machines apart from other ventures into Foursquare-to-physical-world interactvity, such as the interactive ad rigged by a German pet-food company last year to dispense samples when passerby checked into it.

So after hacking a cheap Coleman cooler to open after a check-in, the company got a contract with GE to set up a 72-year-old fridge to open briefly after 10 check-ins, then close until the next 10; it stocked the fridge with beer and set it up at the SXSW Interactive conference in Austin. The Social Cooler, in turn, debuted two weeks ago at an advertising event in New York after an investment of about $800 in materials and 50 person-hours of work.

WIDE ANGLE: Social Networking

Why go to all that trouble? Besides the enjoyment of a good hack, Corbett noted some consumer-use possibilities–maybe setting up a cat-food dispenser to respond via a Twitter direct message ("@PetersCatFood #Monday"), so you wouldn't have to install a separate app.

But the real reward is socially-aware advertising. "From a marketer's standpoint, you want people standing around and interacting with your brand," Corbett said. And the more people sucked in, the better: "You could have Lady Gaga pop out of a cake at halftime only if two million people checked in or tweeted."

Credit: Rob Pegoraro/Discovery