There was this recent kerfluffle regarding their archiving Greatful Dead live performances, and someone told Dave Morey (ALL HAIL!) during his morning show at KFOG about the site, and what the stink was about. In short, the Dead always allowed recording at their shows, and somehow even with rampant trading made more money then almost any other band during their touring career. Of course, that pretty much dried up once Jerry died in '95 -- rumor has it that SOME band members (cough*weir*cough) suddenly realized that they could be making MONEY on all those recordings, especially the sound board recordings (often, though not always, the best in terms of quality) -- only they couldn't do that if people could just download them.
The outcry was so load that they reversed the decision... so I wandered over to archive.org to see what I could see.
Folks, you have GOT to check it out -- there are old safety movies (remember the ones they used to show in health classes in the 60's and 70's?), An OBSCENE number of completely free live recordings from many artists known and obscure, and even some old digitized books and cartoons (I saw at least one WWII era superman short!)