Since 2001, I’ve read (and at some point, implemented) most of the popular productivity books & systems. By far, my favorite is “Connections” by Roger a Merrill, co-author of the 7 Habits of highly effective people. His book predates the 7 habits, and focuses on Quad 2 productivity. It is both philosophical, and very practical.
If anyone has the book, or is willing to purchase a copy, I would be willing to host a book club, either via Skype or in this forms.