Not only was this a long book, it was an intense book requiring a ton of concentration. However, it was well worth the effort. Irving Stone brilliantly detailed the life of Charles Darwin and it was completely fascinating. Darwin's The Origin of Species is 150 years old (give or take) and becoming immersed in the world of the 1830's - 1880's reminds you how much the world has changed.
In the 1830's these people were just learning about dinosaurs, and science wasn't even an accepted practice really and if they wanted to travel it was via long sea voyages. They didn't even have typewriters. Compared to what we know today and the technology we have today and the way we travel, you really have to admire these men like Darwin and his compatriots (one of them being Aldous Huxley's grandfather) for what they endured in the name of discovery.
It took extreme courage and conviction for Darwin to publish what he did in that time. To take on creation and thus the church.
What's most interesting (and my really long way of getting here) is that in spite of the vast differences in the world today and the world of Darwin's day, people remain polarized on the issue of creation. Very little on that has changed and when you put that in perspective, it sort of boggles the mind.
This book is out of print, but I highly recommend it. You can get it used from Amazon or Alibris. Incidentally, I'm not a science person at all ... so this was a real departure for me, and I enjoyed it.
My complete 2008 list can be found here