Military robots, as we think of them, date back to WWII and the Cold War. Today, an experimental weapons system can automate artilary loading and perform ballistics calculations required for accurate predicted fire, all within a 12-second response time. Thankfully, military weapons aren't supposed to be fully autonomous: The Geneva Convention requires human input at certain points to ensure that targets are not within restricted fire areas under the laws of war.
That doesn't mean that there aren't other robo-projects leaping straight from our nightmares to the battlefield. Boston Dynamics, the robotics company behind AlphaDog, Petman, and Cheetah have created a new brick-hurling machine. BigDog is an exceptional mechanical feat: At only 3 feet long and 2.5 feet tall (about the size of a Labrador), it can throw 50-pound blocks of cement. Astonishingly, it matches human behavior, shifting its weight back and then fully forward into the throw. Check out BigDog in action: