Harvard is developing a series of super-fast robot spiders. Created by PhD candidate Andrew Baish these micro-bots, known as the Harvard Abulatory MicroRobot (HAMR), are the size of a penny and can travel faster than a Cheetah.
Weighing in at 0.27 grams, these miniature monstrosities are capable of moving at 8.4 body lengths per second, becoming something of a blur in real-time. Only when slowed down can you see the robot is every bit as insect-like as its appearance suggests (though it would be remiss of me to not point out that spiders are actually arachnids); the robot is capable of carrying several times its own body-weight, as many insects can, and its legs are operated by tiny piezoelectric actuators; that is to say, a small moter that transfers electricity into kinetic pressure, in this case a back-and-forth movement on a timer of 70 per second.
These actuators currently cannot travel far without a power source due to consuming hearty amounts of electricity, and so until battery technology is significantly improved we needn't worry about the prospect of thousands of tiny mechanical spiders skittering up our flesh delivering thousands upon thousands of small lethal injections via syringes on the tips of their spindly legs.
So that's good.