Excluding application-specific shortcuts, these are the Mac OS X shortcuts I would be lost without:
1. CTRL+OPT+CMD+8 – Invert screen
This is useful for 2 reasons. Firstly, it reduces the brightness of the screen, making it easier on the eyes at night and secondly, because it reduces the amount of power needed to run the screen because black pixels take up less energy than white ones. This is helpful when writing word documents or viewing web pages with lots of white-space. Also, it makes people go:
“Wow! How’d you do that?”
2. CMD+OPT+EJECT – Sleep mode
I use this all the time when I run out of the room. Some people set up a hot corner on their desktop, but I prefer the keyboard shortcut because my hot corners are set up for the screensaver functions (now/never), the expose, and the show desktop functions.
3. CMD+OPT+ESC – Force quit program
Not many Mac users know of this shortcut, purely because Mac users don’t have to force quit applications even half as much as the rest have to CTRL+ALT+DELETE them. From here, you can also restart the Finder in the rare case that the dock stops responding. The force quit dialogue also has a lot lower chance of crashing compared to the task manager in Windows.
4. CMD+SHIFT+3 – Screengrab
Windows users have a ‘Print Screen’ button which copies the screengrab to the clipboard. Not very clever when you have to do 10 in a row. The Mac shortcut takes the screengrab and saves it to the desktop in a lovely PNG format for you. Derivations of this shortcut include CMD+SHIFT+4 where you can drag out an area of the screen to capture and CMD+SHIFT+4+SPACE BAR which (quite ingeniously) allows you to capture a single window.
5. CMD+D – Go to desktop
If you are in a ‘Save’ or ‘Save as…’ dialogue box and the default folder is several levels into your computer, simply hit CMD+D and bingo! Your desktop folder becomes active to save onto. This is something I use more than I realise and I get frustrated when I use this on a Windows machine and nothing happens!
If you can think of any more that I haven’t mentioned, or you have something to add, please leave a comment to let me know!