Say you’re working in a given application and you want to hide it. Maybe you’re taking a break, or maybe you just need to get a quick look at the desktop–to quickly find something or email a file. You could use Expose, if you have it set up. You could also choose Hide (application) from the app’s menu. You could even Hold Command and hit H. OR you could hold Option and click anywhere on the desktop, which is my new favorite. Try it.

Hide application: With the application you want to hide active, simply Option-click the desktop.