SF asked for this on the Campfire thread, and I thought it would be a great resource for all.
Disney shows outdoor movies at Beach Club, Fort Wilderness, and All Star Music.
Disney World Outdoor Movie Schedules
May 2008 CSR 
You forget how many great movies they have to choose from until you see them listed there. That would be so much fun!
I think it's a great thing to try if you're there for a lengthy visit and have a free evening. I wouldn't try to fit it in if you're strapped for time...at that point I need to use all of my free time to rest up!
May 2008 CSR