Newton's Law -- One's affinity to Newton is directly proportional to how well it recognizes one's handwriting. -Ross Scott Rubin. [However, it is fun to consult the Newton Oracle by drawing squiggles in the NotePad and seeing how it interprets them. And then there's the Newton's unfortunate predilection for recognizing "call" as "kill" - a wee problem when entering to do items. -Adam]
Sleep (and Lock) Your Screen
When you are walking away from your computer, it's fairly common practice to start your screen saver and lock your screen. But did you know that there is a built-in keyboard shortcut in Mac OS X to sleep the screen?
Press Control-Shift-Eject and your monitor sleeps without engaging the screen saver.