One of the main new features when Panther was introduced a couple of years ago was the introduction of a newly designed Finder, including the sidebar to every finder window.

You can customise this sidebar by adding icons to it, such as commonly used applications and folders. For example, if you use iMovie a lot, open your applications folder, find iMovie and drag it to a position in the sidebar. Notice how the other icons shrink and slide away to make room for the new icon.

You can use this icon just how you would use it in the dock: Click on it to open the application, drag a file over it to open it in the application, and just drag it out of the sidebar to watch it vanish in a puff of smoke.