In Postsingular, a mad scientist creates a race of nants -- nanites -- that digest the planet and turn it into a computational simulation of Earth, called Vearth. However, an autistic child memorizes a long string of numbers that poisons the nants and causes them to reverse themselves (luckily, they're engaged in reversible computation) and put the planet back. That's the setup.
Some time later, another race of benign nanos are released on the earth, the Orphids. Orphids are mezzoscale computers that organize themselves into an intelligent global network, tapping into every human brain and giving people access to outboard cognition facilities, so that anyone can drop out, tune in, and become hyperintelligent. The orphidnetters are haunted by spooks from a parallel dimension, who seek to prevent them from using the smarts of the orphidnet to develop interdimensional travel.
The novel continues in this vein for some 300 pages, each one funnier and weirder than the last. Rucker retired from teaching at UC
Santa Cruz San Jose a few years back and he's been writing his ass off ever since. UCSC's SJSU loss is science fiction's gain.
Rudy Rucker's paintings
FLURB: Rudy Rucker's new literary zine
Rudy Rucker's science fiction webzine Flurb #2 is out
Get Illuminated podcast #3 with Rudy Rucker
Rudy Rucker explains how to get high on cellular automata
Jack Black to star in movie adaptation of Rudy Rucker novel
Rudy Rucker and Rudy Rucker, Jr. short story
Rucker's transrealist 16th-Cen painter novel -- w00t!
Update: Phil sez, "Rudy taught at San Jose State University. Some people are sensitive about these alma mater issues. It's still UCSC's loss. "