We just saw the Howl exhibit at the Cartoon Art Museum. Amazing huge non-photorealistic 3D renderings of stills from the animation, tons of concept art and story boards (including, surprisingly, work from The Norm's Michael Jantze), and photos of beat poets taken by other beat poets. Totally worth checking out if you're in downtown San Francisco.
(Fans of the poem will also want to track down the Kronos Quartet's Howl USA, featuring avante garde string music over recordings of Allen Ginsberg, I.F. Stone, J. Edgar Hoover, and more).