I have also seen a video of one of the Acid Tests (I do not know if it was the first or the "Graduation").
All of these (and more) are available from Key-z.com.
There is also a little bit of footage of the Acid Test Graduation on the DVD of Mondo Mod/The Hippie Revolt. It is an interesting time capsule of old explotation documentaries. Johnny Legend and a video store owner provide an alternate commentary track where they discuss what they were doing on the Sunset Strip in the 1960s. Neither is conscious of what the Acid Test Graduation was though nor do they recognize Kesey, Cassidy, etc.
I would love to see videos of the double-takes of the Rednecks of 1964 reacting to the first Hippies on the Planet Earth as the Bus drove thru the Deep South.