Among 'smart' technologies on show at the Sentient Cities exhibition was a bench that tips people off if they sit too long
It may look like an ordinary rubbish bin, but don't let that fool you. Throw an aluminium can in here and you'd be none the wiser, but try chucking a plastic bottle away, and with an angry buzz it will throw it back out at you, fans whirring to rid itself of the wrong kind of rubbish.
This is the 'smart trash can', part of the 'Toward the Sentient City' exhibition in New York, which explores how our lives might change when we can embed computers in anything and everything.
This fussy recycling bin is the invention of David Jimison and JooYoun Paek, who also created a street sign that points at passersby, and a park bench which tips people off if they've been sitting on it for too long.
David and JooYoun say they want to explore what might happen if technology went wrong in the city of the future, and make us think about our attitudes today.
"It raised concerns about safety - people mentioned 'my grandmother would be hurt if she was dumped off a bench', and it also raised concerns about the homeless", says David.
"Those are precisely the issues we were hoping to bring up, we were interested in talking about public policy in the future, but also where it inhabits our current life - for example, benches today are designed so they can't be slept on."
That vision of the future is one of five projects commissioned for the exhibition by the Architectural League of New York.
The others include 'Trash Track' by a team from The Massachusetts Institute of Technology (MIT) in Boston, who attached smart tags to hundreds of items of New Yorkers' rubbish, so they could track each one from the moment it was thrown away.
'Amphibious Architecture' is the brainchild of a team at New York and Columbia universities who floated sensors and lights in two of the city's rivers, so that just by sending a text message, people can find out what's living down there and what the water quality is like.
A network of plants that kills off the least energy-efficient ones
'Natural Fuse' by Usman Haque, a London-based architect, who created a network of houseplants attached to the electrical system, which monitor energy use - if the system's members use too much power, some of the plants are killed, but if they collectively reduce their energy use the plants thrive, increasing their ability to capture carbon, and the energy available to all.
The potential for technology to change our behaviour, for example by helping us engage with previously unseen places like rubbish dumps or rivers, or by holding our houseplants hostage, is a common theme, and one which the exhibition's curator, Mark Shepard, says he hopes will encourage debate about how we want our cities, and our lives, to change.
"It's not about a fascination with the novelty of technology - the intention was to look at the social, cultural and political implications of these new technologies", he says.
"We're probably not worried if 'smart' traffic lights can better control the flow of cars on our city streets, but some of us might be annoyed if, as we walk past Starbucks, a discount coupon for our favourite drink is beamed to our mobile phone.
"And many of us would protest if we were stopped trying to get on the subway, because the turnstile had 'sensed' that our purchasing history, patterns of travel and current galvanic skin response happened to match the profile of a terrorist. We have to ask now what happens when the system fails, not after the fact."
Will escaping the office make for freer meetings?
While the other exhibits show how invention and cutting edge technology could be used in the future, perhaps the simplest of the projects 'Breakout!' concentrates on changing how we use them.
Anthony Townsend and Dana Spiegel have spent years installing free wifi in New York's parks, enabling people to get online almost wherever they want.
Now they are trying to encourage people to use that freedom to escape their offices, even holding meetings outdoors.
They are leading by example, working on the street almost every day while the exhibition is running, to show people that it's easier than they think. On the day I meet them they're in Philadelphia looking for a suitable spot, but icy winds are making things rather difficult.
Internet access, comfortable seats and tables and nearby toilets are the essentials you need to find, they tell me.
Finding shelter is high on my list, but Dana and Anthony say that's not a problem, as there are plenty of public atria which you can work in without returning to the confines of the office.
They've brought with them a rucksack filled with supplies - a laptop, a wireless router and a battery-powered printer are the most hi-tech, the rest of the bag contains post-it notes, chalk, paper weights and a mini white board, not at all futuristic.
But why bother leaving the office, where you have everything you need already? "It's about reclaiming public space and working better", says Anthony. "Offices are good for clerical work, and that's about it.
I work in about four different places on a regular basis, and now, for example, walking around Philadelphia, I'm completely stimulated.
I can go back to an office to write, sure, but I can't get inspiration there. I want to help other people get the benefit of that."
It's a message, says Dana, that's been positively received: "At first people think it's a spectacle. When do you ever see a group of people holding a conference meeting in a public park? But then they just get it. After all, it's not a strange activity, it's just happening out of place."
But how real are these visions of the future? Could we find ourselves texting the wildlife, following our litter online and using houseplants to control our energy use, all from our office in the public park?
It may seem outlandish, but Gregory Wessner from the Architectural League of New York says it's closer than you think. He tells me that as part of the exhibition they invited the architects Kohn Pedersen Fox and experts from Cisco Systems to give a lecture.
The two companies are working together on two new cities, one in China, the other in South Korea, in which all the information systems, including residential, medical and business, will be linked.
"How it will work, and whether it's good or bad, I don't know", he says. "But the first buildings have already opened, so it's happening, at least in some parts of the world, right now."
It seems the sentient city is here, whether we're ready, or not.