Mark Forster is the author of three books about time management and personal organisation. The most recent, Do It Tomorrow, was published by Hodder in 2006.
Haven't read it Mark, but I can tell you that Steve Zaffron was a top trainer with est, and now head of Landmark Education's (Forum) business consulting group.
What you might find with some books that are influenced by these kinds of groups is that there's a heavy emphasis on language and that you sometimes have to read them a few times to really get the concepts.
Mark, I just remembered an article in Fast Company that I read a few years ago - it's called The Power of Words. The est / Zaffron stuff was partially based on the work of Fernando Flores, the subject of the article.
What you might find with some books that are influenced by these kinds of groups is that there's a heavy emphasis on language and that you sometimes have to read them a few times to really get the concepts.
If you like that book, you might like Benjamin Zander's talk on TED:
http://www.ted.com/talks/benjamin_zander_on_music_and_passion.html
and the book he coauthored with his wife:
http://www.amazon.com/Art-Possibility-Transforming-Professional-Personal/dp/0142001104/ref=sr_1_1?ie=UTF8&s=books&qid=1269709195&sr=8-1
Also Susan Campbell's book "Getting Real".
http://www.fastcompany.com/magazine/21/flores.html
And another one you might find interesting if you got value out of the book:
http://www.walden-family.com/public/cqm-journal/rp07900.pdf