More fantastic robots! These ones are inspired by one of the creatures I find the most fascinating: snakes.
This little guy from Carnegie Mellon Biorobotics (still tethered to its power source and remote control) can move in all kinds of ways; as the video says, not just slithering. Quite a few of these types of movement are actually very simple repetitive motions, while others are much more complicated, with more steps in the movement.
Their page offers videos of several of these gaits which are each useful in their intended environment. Check out the video on cornering:
While this may not look particularly dramatic, it's exciting for things like, say, search and rescue in an unstable or collapsed building. This robot snake with a camera head can travel in a space the width of an I-beam flange and turn corners, without falling down. (Notice the hands ready to catch the robot at the bottom of the video - the tail tether probably pulls it a bit to the side toward open air, so they were being careful.)
Another snake-inspired robot developed more recently but which doesn't look at all like a snake, is Scalybot from Georgia Tech. In this case, it's a robot that has belly scales like a snake's, and uses the robotic equivalent of of a snake's linear travel - no slithering.
Watch closely in the close-up shot to see the belly scales stand out from the body instead of lying flat and smooth like they usually do.
Scalybot kind of stumps along instead of moving with that graceful muscular ripple, but it has similar belly scales, and can control the angle they're standing out like a snake can, so can climb all kinds of slopes and terrain by controlling its friction on the surface.