The way these fish swim is interesting, but the most fascinating thing is that they can sense electric fields around their bodies:

http://www.hizook.com/blog/2010/01/14/bode-plots-fish-awesome-electric-field-sensing-fish

(RE: the above link, how cool is it that they've made Bode plots of the fish's motion? That's something any good engineer can appreciate!)

This same form of sensing has been used by other robots; for example, here is a robot using electric field sensing to plug itself into wall outlets for automatic recharging:

http://www.hizook.com/blog/2010/01/03/self-feeding-robots-robots-plug-themselves-wall-outlets