Here's another thing I customized in my new Tiger OS. I had grown to really like the old Safari behavior with PDF files, where it would simply download them. This allows me to choose what PDF viewer to use. If it's a simple file, then I use Preview. If it's a form or if it contains annotations or other advanced PDF features, then I use Acrobat. I don't prefer the default behavior of the new Safari 2 browser, which will display the file within the browser. Here's how I reverted to my preference.
I simply edited the file ~/Library/Preferenecs/com.apple.Safari.plist using Property List Editor. I added a child named WebKitOmitPDFSupport of the type boolean with the value Yes. That did it. When I tried to accomplish the same thing using the shell command "defaults write com.apple.Safari WebKitOmitPDFSupport -bool YES" nothing happened. I even did it with Safari closed. hmmmm Well, it's no big deal. It got done.