Self-replicating machines are ...
Some proposals involving self-replicating machines include:
1) RepRap Grand Prize ( http://gadaprize.org/ ) is an open source competition that started at Foresight Institute to leverage competition between innovators to improve RepRap. It's an open source, freely-downloadable 3D printer that aims to eventually make all of its own parts. It's spawned businesses like Makerbot Industries, MakerGear, and Aleph Objects. The interim prize ends December 31, 2012 and is fully funded at $20,000. The Grand Prize was announced in January 2010 and ends December 31, 2015 with a targetted prize pool of $80,000. Documentation and rules & terms available on request.
9) SKDB ( http://gnusha.org/skdb ) is a set of standards for open source hardware to make it possible to download hardware over the web. By interfacing with CNC machines, RepRaps and 3D printers, a computer can write instructions specific to an end-user's inventory to make some target system (hypothetically, say an electric spaceplane, or a smartphone). Funding is sought to pay for help to take open source hardware out on the web and put it into a standardized format in a common, public repository. $10,000.
11) Global Village Construction Set ( http://openfarmtech.org/ ). Marcin Jakubowski has been working on a virally replicable village construction set on a farm in Missouri, basically the infrastructure necessary for seasteading minus the parts about living on the sea. Marcin has a TED talk coming up later this year and is presently seeking $1.2M in funding. Documentation & videos available on request.