I've dabbled with Keynote, but usually we are working with pre-existing MS Powerpoint presentations sent to us that we modify as needed. However, the next time I am building a presentation from scratch, I'll probably use Keynote. I've been slowly converting various templates and sell-sheets into Keynote's companion, Pages, which works a hell of a lot better for simple layout than MS Word. Occasionally, I'll try InDesign CS2, but often it is overkill for a simple page or two piece.
Apparently, Al Gore is a fan of Keynote, and used it for his movie:
Apple - Key to “An Inconvenient Truth”
“I’m guessing it’s the first time that a feature film or documentary has ever been made with Keynote as its basis,” says Lesley Chilcott, coproducer of the Sundance Film Festival hit
More here about the design team.
Link via Kottke
