"BackTrack 4: Assuring Security by Penetration Testing", it was an eye-opener. I hadn't heard of "BackTrack" before, the idea of a whole Linux distribution full of security penetration tools was something I never knew existed. I learned some valuable things about security from that book.
Time has gone on, and BackTrack has added to it's capabilities. Packt has kindly provided a book that explains what's new, including what appears to be some neat chapters on Wireless networking and Voice Over IP. I'm curious about those, it should be an interesting read.
The book is described here.
Watch this space for a review soon!
Happy (secure) computing!