This is about two weeks old so the quasiomniscient Anders Sandberg may have already posted this and i missed it. If this is the case, i apologise for the noise.
Building Molecular Machine Systems by K. Eric Drexler which is a
pre-print of an article published in the January 99 issue of Trends in
No new science but like anything written by Drexler, good for the soul :) chau