Boston Dynamics' Cheetah
Boston Dynamics' "Cheetah" robot just broke its own speed record. This in and of itself is quite an achievement, considering it was already the fastest legged robot in existence, but it also broke Usain Bolt's record (100m and 200m sprinting world champion)! The cheetah robot was able to achieve 45.5 km/hr, smashing Usain 's record of 44.7 km/h. Take a look at the impressive video:
It is important to note that humanity's fate is not yet sealed since the robot was running on a treadmill while tethered, so the energy it used to move its legs was not onboard, making it considerably lighter. Regardless, this is the fastest legged robot and Boston Dynamics plans to start untethered tests in 2013.