A book like this (and really there is just one) is bound to pique not just a few people, and for contrary reasons depending on their viewpoint. Some here have wondered if Tipler is trying to pull one over on them and others, but one can be assured that the physicalist arguments in this book are for real: Tipler's Omega Point Theory first appeared in book-form at the end of _The Anthropic Cosmological Principle_ (1986) co-written by cosmologist John D. Barrow and Tipler, of which said book received almost universally fawning praise by the science media; and while the implications of it there were clear enough to anyone paying very close attention, Tipler did not in that book mention the resurrection mechanism or equate it with God--but infinite computation by any other name would still be as Godly. A later book to come out after _The Physics of Immortality_ which in part presents and defends Tipler's Omega Point Theory is the excellent _Fabric of Reality_ (1997) by physicist David Deutsch (inventor of the quantum computer and winner of the Institute of Physics Paul Dirac Prize for his work in the field). Thus it cannot be very well maintained that Tipler is some sort of kook or fraud--he is by no means either, and this Theory demands to be taken seriously by anyone who is serious.
Some have reported that not even Tipler believes in his own Theory, and it is true that Tipler did say this in the first part of the 12th chapter of _T.P.O.I._ (and in addition stating that he was still an atheist), but this just goes to show how intellectually honest Tipler was being in presenting his Theory--other than theoretical beauty he did not at that time (1994) have any confirming experimental evidence for it--but he also stated that if the Omega Point Theory is confirmed then he shall consider himself a theist. That was seven years ago, and things have progressed since then. For one, the top quark has been found (in 1995) with the mass as predicted it would be in the Omega Point Theory. Also, Deutsch derived the Omega Point using a completely different methodology (using the Turing principle) in the 14th chapter ("The Ends of the Universe") of his book mentioned above--as a matter of fact, this chapter is available on-line at Tipler's homepage (and with Tipler's replies to it) for anyone willing to do a search for it (which I advise). But probably most convincing are the arguments on the physical restraints (e.g., the Bekenstein Bound, general relativity, and the Second Law of Thermodynamics) which seem to _require_ that the universe evolve into the Omega Point in order for some of the most basic laws of physics to be mutually consistent (such as unitarity not being violated)--of which arguments are a later development than Tipler's book, _T.P.O.I._, and so were not included in there (see the Wired article by Tipler called "From 2100 to the End of Time," which is available on-line by doing a search; see also Tipler's homepage). "I'm very encouraged by all these things. It's developing much more rapidly than I had expected," Tipler has told USA Today columnist Sam Meddis--"I'm far more confident now." How much more confident? He's no longer an atheist. (The four-part USA Today series by Sam Meddis on Tipler's Omega Point Theory is available on-line; locate it by doing a search.)
And some have claimed that the recent supernovae data suggesting that the universe's expansion seems to be speeding up shows that the universe is open, as opposed to closed, which would obviate the Omega Point (since it requires that the universe be closed). But as Michael Turner and Lawrence Krauss have demonstrated in a recent paper (_Geometry and Destiny_ [Apr. 1999]; astro-ph/9904020--also available on-line) the supernovae data do _not_ show this. But moreover, the laws of physics _require_ that the universe must end in a finite time, which is only possible in a closed universe. As Hawking has shown, black holes evaporate over time, but if black holes were to evaporate completely away before the universe ends then quantum information would be lost and unitarity would be violated! But unitarity is one of the central postulates of Quantum Mechanics, confirmed again and again by every experiment to date--and indeed, quantum computation would not be possible without it.
In short, I highly recommend this book to any sapient person--along with David Deutsch's _The Fabric of Reality_. Both of these books are real mind benders, but in a good way. Any debate between atheism and theism which does not oft reference these books is still in the dark. Religion has now been subsumed by physics.