Warning: Wikipedia contains spoilers.
Permutation City asks many of the same kinds of philosophical questions as The Matrix, Blade Runner and Ghost in the Shell -- does anything differentiate a perfect computer simulation of a person from a "real" one? -- but its textual nature allows it to push the ideas further. Egan gleefully deconstructs and undermines traditional notions of self, future, personality, and even physical reality.
A loose sequel, Diaspora was published in 1997.
Its ISBN number is ISBN 1-85798-218-5.