There is not nearly enough nerdy content up there, if any, so I thought I would share what books I am reading right now. Maybe that could be a topic, "What are you reading right now?"
Groovy in Action
Great reference book on all things Groovy. I am continually amazed at how Groovy makes Java fun again. Can you say "Closures" anyone?
The Definitive guide to Grails
Like Ruby on Rails, its Groovy on Grails. This is a Web application framework built on top of Spring and Hibernate. Unlike Struts, Spring MVC, etc. this framework is developed using Groovy. You can still write Java code if you need to or reuse existing Java sources but you won't want to!
Patterns of Enterprise Application Architecture
While this book is a little dated, it still shines as a great reference for me. A lot of the patterns in the book are just now getting recognition as being simple and elegant.
Spring in Action
Having read through this book once, it still serves as a great reference. If you want a thorough introduction to Spring, this is the book for you.