In Macromedia Flash, I use Ctrl+F12 to publish the flash movie.
Some use F12 to publish and preview, but since it keeps trying to open IE, I never use it that way.
In Adobe Photoshop, F12 is the default shortcut for "Revert" which gets some uses from time to time when you mess up something real bad.
That's on windows. I have no use for it yet on my linux desktop.