Quick Look is a handy feature of Mac OS X that allows you to preview a file simply by hitting the Space Bar while the file is selected. A large preview window opens allowing you to see what the file is (provided the file format is supported by OS X.

Open files with Quick Look

Quick Look can open files with a simple mouse shortcut

With OS X Lion, you can open the image by clicking the small button in the upper right corner of the Quick Look window, but it’s much easier to simply double-click the Quick Look window. Not a huge time-saver, but every click saved is a click earned, I always say.