Your cell phone is able to vibrate because there's a little motor inside that rotates a small, off-balance weight. We've all seen our phones skitter across a desk when a call comes in, some further than others, depending on what model you have. But the phone's locomotion is not directed or intended, it's just a side effect of this little device spinning inside.
What if that motion was directed, and even precisely predetermined? Independent of cell phones, researchers at Switzerland's Institute for Dynamic Systems and Control designed and built the Cubli, a 15-cm cube that can move around by means of little flywheels, motors and sensors inside of it. While a cube is not the shape you think of when you think about designing a miniature vehicle, check out what this thing can do:
I'm going to forego my usualrobophobictirade about the borderline creepiness of a cube that can move like that, and instead propose that these guys make my cell phone silently stand straight up on my desk whenever a call or text comes in.