I can – correction, have – watch things like this for hours – the source material for Star Wars. This video has an unusually good history focus. If you’re just into the shot-by-shot stuff though, it starts at the 6:20 mark.
One of the most comprehensive video comparisons, of course, is in Kirby Ferguson’s “Everything is a Remix”, the Star Wars segment has been chopped out below.
And for serious fans – 8:30 minutes of the Mos Eisley Cantina scene, intercut with its original sources (including 2001: A Space Odyssey, Casablanca, Yojimbo, The Good, The Bad and the Ugly, and The Magnificent Seven).
Film School’d clip via Kottke.