I’m currently writing a brand new presentation (more on this later) and I find myself in need of a feature I had never thought of before.

I’d like to create two versions of this presentation: one that fits in forty-five minutes and one in two hours, the longer version being a superset of the shorter one: it just contains a few additional slides here and there.

Is there any other way for me to do this besides having two separate files with a lot of slides duplicated?

Ideally, I’d like to be able to put my slides in groups: some will be in the “short” group and other will be in both the “short” and “long” groups. When I start the presentation, I tell the software which group I am showing today (this idea will undoubtedely sound familiar to TestNG users :-)).

The closest I could find in PowerPoint is by hiding/showing individual slides, which is really impractical.

Does anyone have a better solution with either PowerPoint, Keynote or even Google Presentation?