I've mentioned in the past that I've yet to see Ian McKellen's Richard III. I may not have to after finding this annotated version of the screenplay, which he wrote.
Wow. It's hosted, you'll note, at Sir Ian's own site - so I have faith in its quality and credibility. Just looking at the first page, all I can say is that if the entire thing is annotated at that level, I'll just go ahead and read it like a book.
I'm already looking at ways to get the entire thing into a Kindle-friendly ebook format so I can take it with me ;)