What can I say?  I'm flattered, as well as happy to know that people enjoy my writing.

As for an OpenACS book, I'm sorta kinda working on one right now.  I recently started work on a book for Apress that compares and contrasts a number of open-source Web development framekworks, including OpenACS.  When the time comes, I'll undoubtedly ask people at openacs.org for help as technical reviewers.