"One of the dreams of both science fiction writers and practical robot builders has been realized, at least on a simple level: Cornell University researchers have created a machine that can build copies of itself. Admittedly the machine is just a proof of concept -- it performs no useful function except to self-replicate -- but the basic principle could be extended to create robots that could replicate or at least repair themselves while working in space or in hazardous environments"
http://video.google.com/videoplay?do...%20replicating
granted they don't do much but it's a peak at the future.
Mike