Read it when it came out.
Great book. I don't want to give too much away, but it's basically about nanobots. Here's an interesting (to me) passage. It's kind of an aside, from about half way through.
"... accelerated... The first life shows up four billion years ago as single-celled creatures. Nothing changes for the next two billion years. Then nuclei appear in cells. Things start to pick up. Only a few hundred million years after that, explosive diversity of life. And more diversity. By a couple of hundred million years ago there are large plants and animals, complex creatures, dinosaurs. In all this, man's a latecomer: four million years ago, upright apes. Two million years ago, early human ancestors. Thirty-five thousand years ago, cave paintings.
The acceleration was dramatic. If you compressed the history of life on earth into twenty-four hours, then multicellular organisms appear in the last twelve hours, dinosaurs in the last hour, the earliest men in the last fourty seconds, and modern men less than a second ago.
It had taken two billion years for primitive cells to incorporate a nucleus, the first step toward complexity. But it had taken only 200 million years - one-tenth of the time to go from small-brained apes with crude bone tools to modern man and genetic engineering. That was how fast the pace had increased."
Don't assume that Crichton or the book are preachy (like me). They're not. It's a great read. You'll like it.