Here is the only bit of software I've ever made available. "Primitive" hardly begins to describe it. It's an AppleScript application that makes it fairly simple to interactively and selectively combine two QuickTime movies into a single presentation file.
There are two download packages:
PBuilder.zip (5.4 Mb) is the complete package which includes the Presentation Builder application, a Readme file, and a tutorial which also happens to be a sample of the output.
PBLight.zip (28 Kb) is the application and readme file, without the sample movie.
The program requires MacOS X.2 or later, and I think it requires QuickTime Pro.
--Dave Althoff, Jr.