When viewing a QuickTime movie, you’ve probably used the View menu to change the size of the playback window. The options on the View menu let you choose between half size (Command-0), actual size (Command-1), double size (Command-2), fit-to-screen (Command-3), or full screen (Command-F, if you have QuickTime Pro) modes. But QuickTime has some other, somewhat hidden, methods available for resizing your movies.
First, if you hold the Option key and drag on the window-resizing triangle at the lower right of the window, QuickTime will resize the movie only to those resolutions it can display most smoothly. Depending on the size of your monitor, this may give you more viewing options than the four provided by the View menu. The other method of resizing, which is mentioned in QuickTime’s Help file (though who reads those?) is to use the Shift key while resizing the movie. With the Shift key held down, QuickTime removes all constraints on the size of the movie. This can actually be useful—if you’ve ever received a clip that seemed to have the incorrect aspect ratio, you can use this trick to set it to something more realistic. (Use the View -> Show Movie Info window to see the original and revised dimensions.)
Of course, you can also begin distorting clips for the sheer twisted fun of it:
Davy Jones isn’t quite so menacing when you make him really short and wide! After you’re done having fun, just press Command-1 and your clip will return to its default size and aspect ratio.