Case-sensitive websites
I've never understood why you would want a case-sensitive webserver. ScotG's blog recently mentioned his purchase of an iSight. Since I don't follow Apple hardware (nor Apple in general) I clicked on his link to the iSight, http://www.apple.com/iSight. I got to an Apple page about it being an invalid link. So I went to Apple's product pages and saw a link to the iSight. I clicked on the linked and when it popped up in my browser, the URL looked like the same one ScotG had in his blog. I went back and double-checked his blog entry: iSight vs. isight.
I'm no marketing guy, but if I were Apple and I was selling a product called an "iSight", I would want http://www.apple.com/iSight to bring me to the page for the iSight...