Wil McCarthy, a scientist and science fiction author, was the Guest of Honor at ApolloCon 2009. He gave a talk on the work he's been doing in programmable matter. He started off by showing the audience a piece of clear glass. Then he heated the glass with a hair dryer. An irregularly shaped reflective blob grew on the glass -- the heat turned the glass reflective. This was McCarthy's demonstration of materials he's working on in his startup.
Definitions and discussion of programmable matter can be found elsewhere on the web, and McCarthy did not dwell on the theory, but talked about his work in this area. His practical work in programmable matter developed from his nonfiction book "Hacking Matter", which it turn was born from his fiction. He talked about the events that lead to writing of "Hacking Matter", and how it attracted investors' interest, leading to creation of programmable matter startup. McCarthy talked about his company's journey to discovery of viable commercial applications for these materials, and why he avoids the word "nanotechnology" for marketing this technology to investors. He briefly discussed weapon potential and security issues of programmable matter with the audience. Finally, he talked about balancing his science and writing careers, or rather, impossibility thereof.
The whole article is available on my web site.
Pictures from ApolloCon 2009 are in my photo gallery.