My former boss had me create a slideshow that showed how the company's IT systems had accumulated over time, which was a helpful way to show how an acquisition could affect a lot of other systems. It also made it easier to visualize how a prospective new project could help multiple other systems.

That's about the only thing I ever really used it for, although I did whip up a quick-and-dirty org chart with it a couple of times. Mostly, I've tried to avoid it, but I think it can have some limited uses.