Ruby Kung Fu
What this about?
This book is a great collection of ideas, tricks, and skills that could be useful for Hackers. It's a unique extraction reference, summarizes a lot of research and experience in order to achieve your w00t in the shortest and smartest way. Rubyfu is where you'll find plug-n-hack code. Rubyfu is a book to use not only to read, it's where ruby goes evil.