So when you're viewing your movie in Firefox, click the fish, and a page with all video links will appear on the screen. The one playing is checked with a green marker. Just control-click on it, select the Save to Location menu item, choose a file name and location, and you're done. The media will download to your disk.
It also works with with popular site like YouTube and more.
[robg adds: There are many ways to grab QuickTime movies from various browsers, but this little plug-in makes it about as easy as possible.]

