Hey Bill,
Love your books and have gone through all the 501 titles numerous times and gained so much from them. Have you considered writing another one and this time naming it something like "Another 501" or "501 more" ?
Thanks for the time.
Thanks for the kind remarks, and glad you liked the book. I don't have any plans for a 501-type book in the near future, although I am working on a new book right now on a different topic.