I build robots - my best effort to date is "Pedro" the quadruped robot dog (see http://robotsaustralia.googlepages.com though that site has now been morphed into a sites.google site and the layout is fairly stuffed now).

I'm also an engineer, and 3d printing is just a natural no-brainer of an addition to the arsenal of tools available like cnc milling etc. Ever since I've been designing stuff on computers I've always wanted a 'print to reality' button, and 3d printing in plastic is about the closest thing around to a sci-fi 'replicator'