Here's something that we're excited to see being used in real life rather than just sitting on a designers hard drive: BigBelly. BigBelly is a public trashcan that can hold tons more trash than a normal trash can because it compacts it down. And it does this without sucking up any energy from the grid or raising a city's energy costs because it has a big ol' solar panel on top.
This saves money by not requiring the cans to be emptied as often, and once the initial investment in the BigBelly is made it costs very little in upkeep. It makes so much sense, in fact, that you can find BigBellys hanging out on street corners in Palm Springs, CA already, and it's definitely not the last city to catch on to the idea.