Without giving away precious information, are there any puzzlers you foudn which didn't quite make it into the book?
Yes. We will try to post one or two as the week progresses.
Do you two have a website with a forum so people can post their own, or discuss the answers/solutions?
The book's web site is www.javapuzzlers.com. Right now it's pretty primitive. We intend to improve it shortly. For starters, we will put up a list of errata before the week is over (our Japanese translator, Yoshiki Shibata, has already found quite a few.) We may add a discussion area to the web site at some point. In the meantime SEND US YOUR PUZZLERS! Send them to firstname.lastname@example.org.
And lastly, what was the most challenging aspect of the writing process, for each of you?
I can't answer for Neal. For me, the most challenging aspects were organizing the material--trying to divide the puzzles into chapters that hung together, trying to maintain the standard of "Effective Java," making sure the book was fun, and getting the bloody thing done in time for JavaOne
Joshua Bloch <br />Author of <a href="http://www.amazon.com/exec/obidos/ASIN/0201310058/ref=ase_electricporkchop" target="_blank" rel="nofollow">Effective Java</a> and coauthor of <a href="http://www.amazon.com/exec/obidos/ASIN/032133678X/ref=ase_electricporkchop" target="_blank" rel="nofollow">Java Puzzlers</a>
The most challenging thing was balancing work on the book with the rest of my life. We spent many evenings working on the book until 2am, but I'd be out the door to drive my daughter to school (and head to work to do my Google job) at 8am the next morning. I think I slept for a week when we were done.
As far as the technical work, the hardest part for me was writing the first draft of the text for each puzzle. I also agree with Josh's answer.