What general age range are we talking about? I think that a lot of traditional field day activities could be redone to be Disney-themed. You could do a Lilo and Stitch limbo (decorate the limbo pole and use music from the movie), a Peter Pan egg toss (paint the eggs like characters-- they can fly!), Princess and the Frog-hop (leapfrogging race with appropriate music and finish line theme)... The list goes on. If a lot of parents come, you can also do a crowd scavenger hunt, and ask them to find Disney movie-themed things. Something that glows like Raymond; a "Happy" person; someone with a shirt "as white as snow", etc. I can't remember a lot of field day events, unfortunately, but hopefully these are a good start!