Boston Dynamics, an engineering company spun off by MIT to develop robots with human-like abilities, is currently developing an engine-driven, pack mule-like robot named BigDog that you have to see in action to believe. (That link is to a Windows Media Player-format video, which plays just fine in the OS X version of WMP.) The movement of BigDog’s four legs is amazing and a bit creepy all at the same time, but the whole package works well enough that it looks like you can actually kick the robot in the side and it’ll recover and continue moving without a problem. DARPA is sponsoring the development of BigDog, which looks like it could someday be a useful military tool for carrying heavy loads alongside troops on foot.