Just finished
http://www.amazon.com/A-Planet-Virus.../dp/0226983358
Planet of Viruses by Carl Zimmer which I picked up as a free ebook a while back. 4/5 stars. Excellent writing as usual. He truly explores the world of viruses and make you realize not only are they everywhere but they may be responsible for life itself. One interesting tid-bit humans would not be able to reproduce is we did not have certain viruses in our bodies and dna.