Last year, we got a peek at Necomimi - a conceptual brainwave reading device, equipped with a pair of cat ears programmed to react based on how you're feeling. For example, eating a cupcake might make the ears perk up with delight, while watching "Keeping Up with the Kardashians" might make them bow in shame. However, if you're like me and would prefer NOT to have the electrical activity of your brain monitored for the sake of questionable (albeit cute) fun, Instuctables user abetusk has come up with a way to replicate the device at home, using a controller to move the ears, instead of relying on those pesky things we call emotions.
Abetusk says, "I wanted to build something that wasn't too expensive and was easy enough to be done in a sitting or two. I picked out some cheap servo motors, some craft supplies, spent a weekend or two developing code to control the servo's from a microcontroller and after much trial and error, I built some kitty ears that I think are pretty decent."
If you have a soldering iron, AVR Programmer, and some black and white craft fur taking up space in your closet, step-by-step instructions for the project can be found here.