Psiga sez, "Wil McCarthy's incredibly compelling book, Hacking Matter (raved about on boingboing some two and a half years ago), has been released in a free pdf form. It's great that the book can now be freely shared." Hacking Matter is a science book about Wil's research on "quantum dots" — configurable "mezzoscale" (larger than nano) machines that can be controleld with software to mimic the properties of different elements.
(Thanks, Psiga!)