I was just thinking how cool it would be to make a octopus-like robot. Low and behold, a group in europe is already working on it - Octopus Project.
IEEE Spectrum speculatedon the videos:
The Octopus Project posted this video to their YouTube channel with zero explanation, but we do know a couple things about it. First, those big tentacles at the front are labeled as "SMA Arms," which means that they're actuated by a shape-memory alloy that changes is length when heated, no servos or anything necessary. The other six arms are silicone with a steel cable inside, and this steel cable is attached to a bunch of nylon cables, and by manipulating those nylon cables, the tentacle can be made to wiggle around and even grip things.