http://www.sciencefriday.com/program/archives/201201134

Bubbles can do computations, says Stanford professor Manu Prakash. Just like electrons running through wires in your computer, Prakash and Neil Gershenfeld, of MIT, directed bubbles through tiny etched tubes and showed basic computations were possible. Because the presence of a bubble can influence the behavior of another bubble, Prakash was able to build "and," "or" and "not" gates.