You are very good at this....do you know these off the top of your head or do you do homework?
I know the art parody ones immediately ( i'm somewhat of an art nerd). I know alot about human marvels too, so I see them all over in GPKs. Some of them I recognize and then search for related images. I saw that Guzzlin' gary looked like Spudz Mckenzie but was suprised to find a pic that looked exactly like the GPK.