I don't know if this has been posted before, or how many people know about this, but I was listening to the radio last night and there was a little feature (which might be weekly) on the Pacifica Radio Archives.

Its fairly self-explanatory, but this group archives public radio broadcasts from as far back as the late 40s/compiles retrospectives with clips and makes them available to stream here: http://fromthevaultradio.org . There's lots of good and really interesting shows, broadcasts of the the Hiroshima bombing report, Ginsberg reading "Howl" and a panel discussion afterwards and other stuff (don't use the left-hand menu if you want to go back further, just keep clicking previous at the bottom of the page)