The Changeling Plague by Syne Mitchell
Either I'm behind on keeping track of the evolution of cyberpunk (weaselmom, your boy should be able to offer advice), or the theme here is a fresh and very cool one: Hackers get involved in genetic coding when a tailored plague threatens to wipe out humanity.
Hugely page-turning, insightful about gene- and DNA-therapy, great characters, and scary as hell.... I hate to admit it, but my biggest problem with the book was that the writer is one of those jerks who started publishing at, like, 12 years old (no offense, tmseay). Heh heh.
I'll be offering book rec's (and anti-rec's) over the next couple of months: Campbell Award reading time!