Permutation City: People can run simulations of themselves or entirely migrate their consciousness into computer programs, but existence is often limited to the amount of computation that you can afford, leading to slow existences that stretch time into fractions of realtime. That premise had me hooked, but the book has fantastic thought provoking plot points throughout. Highly recommended.

Then in my grad school work, I randomly ran across his name and have subsequently read most of his books.

Diaspora, however, remains my all time favorite novel.