Dude. This is the coolest thing. Evar.
Concert Vault is a virtual shrine to legendary concert promoter Bill Graham and opens up the Bill Graham Presents archives to share with The Great Unwashed.
Go to Concert Vault, register, and listen to recordings from past BGP concerts, including Bob Marley and the Wailers, Echo and the Bunnymen, The Who, Steppenwolf, David Bowie, etc. Concert recordings, people. Each listing also gives you the play list, musicians that played that night, and puts the concert in context within the career/lifespan of the band.
Wolfgang's Vault also contains old poster art, laminates, backstage passes, and vintage t-shirts.
Freakin' awesome, I know.
Thank me later.
(Props to Brion for the tip. He's just a *little* cooler than I. Just slightly.)