Last night, I went and saw the Pixar-20 years of Animation exhibition that's on at ACMI in Melbourne at the moment. In a nutshell, it was awesome. I'll definitely be going again before it's finished. Basically, they've got on show a lot of the concept art and visual development material from their films. Lots of character concepts, colour keys, background concepts, and sculpted models of the characters. It was great to see the different materials used and scribbled drawing on scraps of paper- drawings that looked like they'd been worked on and not polished pieces of finished art. To see the actual pieces that I've seen in books was a huge treat. In particular I found the Zoetrope that was on display amazing.
I'm also developing quite an appreciation of colour keys.
If you are in Melbourne or can get to Melbourne, I'd highly recommend paying a visit.