Official Google Webmaster Central Blog: Optimize your crawling & indexing
handy tips from google on making your site crawler friendly
ShadyURL - Don't just shorten your URL, make it suspicious and frightening.
danwebb.net - It's About The Hashbangs
After quite a lot of thought and some attention to some of the issues that surround web apps that use hashbang URLs I’ve come to conclusion that it most definitely is about the hashbangs. This technique, on its own, is destructive to the web.
danwebb.net - It's About The Hashbangs
The History of the URL: Domain, Protocol, and Port - Eager Blog