I just completed a project in iMovie 11. I would like to save a copy of it that I can play around with and edit. I still want the original movie though. How do I save a copy of it?
In the Project Library view, click on the project that you wish to copy. From the iMovie menu, select File>Duplicate Project. An exact copy of the original project will be placed in the Project Library. It will have the same name as the original, but with a number appended (number 1 if this is the first duplicate). The duplicate can be renamed if desired. It can be edited in the normal way, without affecting the original project.
The duplicate will not take up much extra space on your Mac or external drive. Projects basically reference (link to) the associated clips in the Event (or Events) and don't contain actual video. The project file also contains information about edit points, transitions, titles, effects, music and so forth.