preferences

For the longest time, I've flip-flopped on whether to check the 'Use all F1, F2, etc. keys as standard function keys' option in the Keyboard System Preference pane.

Many a Mac user has never set foot into the realm of the "Universal Access" System Preference pane, and I believe that's a shame. There are so many useful, and, dare I say, awesome things you can do in that area of System Preferences:

And a quick guide to some of the coolest features: