My favorite short cut

Switching quickly between open applications.
Without a doubt my favorite Mac tip is a global keyboard shortcut. I tend to work with 3 to 4 applications open. You can go to the dock and click on them but that's not real fast. If you hold down the Command key while you press Tab you get a little window in the middle of your screen showing all open applications. Continue to hold down the Command key. Now you can either move the mouse over the one you want or keep pressing the Tab key till the one you want is highlighted then release the Command key and that application will become the active app. Here's the really cool part. The window arranges the applications with the latest on the left to the oldest on the right. This makes it real easy if you are pasting things between 2 applications. The last app you used is always one tab away.