A group of developers thought it would be fun to merge playground activities with mobile gaming -- so they did. They've created a system called Hybrid Play that lets kids (or adults, no judgment here) control games on their phones with see-saws, swing sets and other playground toys. To transform these outdoor playsets into big controllers, kids will have to clip the Hybrid Play sensor (above) onto their slides and merry-go-rounds. This sensor (which is dust- impact- and water-resistant) is powered by an Arduino microcontoller and equipped with accelerometers, gyroscopes, infrared and Bluetooth. It transforms real-life movements into signals sent to your phone, which the app then converts into virtual action. By the way, the system's iOS and Android apps will come loaded with a selection of games to choose from, but everyone can make their own, as it's an open-source project.