Just a nice little touch I've just noticed in Safari: if you type file:/ in the location bar, you'll see the favicon change to show the icon of the folder or file you type in. So file:/Applications shows the Applications folder's icon, file:/Applications/Safari.app shows the Safari icon, etc.
This also happens as you type -- very nice!
Mac OS X Hints
http://hints.macworld.com/article.php?story=20060905063035917