I have also found Eat That Frog to be an unusually good collection of the major productivity techniques. Incidentally, I also heard about the book from Patri via Divia.
For a shorter and more rationality-friendly version of the book, I summarized it here:
EDIT: http://becomingeden.com/summary-of-eat-that-frog/
Thanks, I’m glad you found it useful! :)