I watched "ILM - Creating the Impossible" on Encore on Demand the other night, and it was well worth the watch. There is quite a bit devoted to the relationship between ILM and Pixar, and a number of historical anecdotes like this article that are very interesting.

If you haven't seen it, check it out before they drop it. Of course, The Pixar Story is worth watching as well (same people, I think).