Desktop manufacturing and 3D printers are beginning to emerge as a growing industry. See RepRap - http://www.reprap.org/ and Cupcake CNC - http://www.makerbot.com/ for two examples. The technology allows you to design a model and have it manufactured in a device about the size of a large inkjet / laser printer. Instead of ink it extrudes plastic onto a platform. By layering the plastic objects can be created.
NASA could work with the desktop manufacturing community to design models for use in 3D printers. There are any number of items that could be modeled - rockets, satellites, the Shuttles, the International Space Station. The designs could be released into the public domain for anyone to use.
NASA engineers could also look into helping to develop the technology behind the 3D printers to make them better.