Just re-read this for the first time, and it's still one of my favorites. This book is geek-heaven: cryptography, world war II, code-breaking, nazi gold, and modern day internet beginnings all tied together in one masterful story. 
 It also was largely lost on me, and I suspect many of my generation, that the second world war was won - or at least greatly accelerated - in great part due to the fact that we had cracked the German and Japanese codes. Learning more about the efforts of Bletchley Park, and Dr Alan Turing and huffduff and cribs, etc was fascinating. 
 I think the funniest part of the book is the page where Stephenson actually graphs out how productive Waterhouse is when he has recently had sex (very productive) and when he hasn't (not very productive). 
 The code-breaking and cryptography is not stuff I know a ton about, as modern day programmers largely don't have to worry about that stuff, but it's a good reminder to think about, as we don't have it on our brains nearly enough. Avi & Randy's paranoia and tendency to encrypt everything from their hard drives to their emails may be overkill, on the other hand, it also may be wise. I remember getting email from people who used public/private keys to encrypt their email before, but not in the last 5 years. Maybe we should request that Gmail Labs add that! 
 If there was a theme to this book, it's that cryptography is everything. It defined the second world war, and it also defines the modern internet. Information is king - not large caches of gold.