Keynote lets you easily embed a QuickTime movie, but what about F4V? After many failed attempts here's what works. Fortunately, it's simple.
- Download and install the Perian drivers so that QuickTime can play Flash video.
- Select the video file to be embedded, Ctrl-click and choose "Get Info".
- Set "Open with:" to "QuickTime Player".
- Change the extension on the file from .f4v to .mov.
- Drag and drop the file into Keynote.