Today, a coworker pointed out to me a feature he discovered in Apple Safari after doing a search for a random error code while writing an Ajax script for This is a very useful feature of safari that I'm surprised they don't allow you to activate just in your preferences.

To activate this hidden debug menu in Safari type the following command into Terminal (located in applications >> utilities):

defaults write IncludeDebugMenu 1

To hide the menu again, just enter the following:

defaults write IncludeDebugMenu 0