I've just received a hard copy of "Dependency Injection" by Dhanji R. Prasanna. This book is great!
If you are not yet a DI user, this book will guide you from beginning to expert use. If you are already a DI user, this book will reveal best practices, patterns, and a surprising number of useful suggestions to enhance your use of Dependency Injection.
Mr. Prasanna is clearly an expert in his field, and he presents ideas in an easy-to-read manner.
DI usage, like Unit Testing, facilitates writing good code. The author covers a lot of ground, making recommendations for coders dealing with AOP, thread-safety, framework design, and others.
I highly recommend this book to any developer!