Greg Egan is an Australian author of uncompromising "hardcore" science fiction. One of his earlier books, Permutation City (Millennium, £6.99 in UK) is set in a near future in which it is possible for people to create "copies" of themselves by mapping their neurons on to computer. Possessing the original's personality and memories, copies are indistinguishable from the "real" thing. Egan's future society is witnessing the beginnings of a mass migration to cyberspace (where you can be effectively immortal, and pretty much do what you like). Unfortunately, cyberspace's denizens also have a propensity to go mad, unable to cope in an environment that evolution didn't intend them to inhabit.

Permutation City is a mind opening and world-view-shattering book. It should be a part of every school's curriculum.