Sure, the Phillips Hue (a light bulb that can be controlled with an iPad) might seem slightly silly, but one dad found a really good way to use it: By helping his son play some Minecraft. Dad #1 Jim Rutherford set up a quick iPad app to easily and quickly sync up the Hue light with wherever the sun is in his son's Minecraft game, and then the app automatically controls the light according to Minecraft's schedule. In other words, the light makes it exactly the same brightness in the real world as it is in the game's world.
It's a very cool idea (and the app also has the added benefit of serving as a clock for the Minecraft game, as well as giving Rutherford some good experience for setting up the Hue). He's now open-sourced the project as well, and you can find the code for it on git. It's as neat a use for the Hue as any, and it's a great way for father and son to bond (and code) thanks to an iPad.