Dug recently posted news of Rob Ives' Downloadable Dancing Diplodocus (say that drunk), one of a range of similar products that combine my love of both automata and digital fabrication - simply pay your money, download the .pdfs, print out and build. Rob's Flying Pig site has a whole department of downloadable automata.
My favourites have to be the platonic solids and and the miniature wind turbine. I like Rob's variety of designs, some of them being simple demonstrations, looking like starting points or bits of a possible larger cardboard machine yet to be published! The nice thing about selling them as downloads is that one is not constrained by the economics of print runs, that part being outsourced to the user, so one can afford to have a wide range of very niche designs, that only a few might buy. Its like the long tail of paper-craft!
All images from Flying Pig