I've put a bunch of new Atari-related things up at archive.org recently. Most of this is (as far as I know) online for the first time.
Atari Christmas 1981 - A silly video created by Atari customer service employees around Christmas 1981. It was probably hilarious at the Christmas party. See what the Atari offices looked like, and some people who worked there. This was provided to me by Kent Smith, who worked there, and whose interview will be online at ataripodcast.com next week.
Atari Computer Camps Logo - just a big ol' TIFF image of the logo.
Atari Computer Product Flyers - some great flyers for early 400/800-related products.
Atari News Bits Number 2 - 1979 (Still looking for #1)
Atari Pilot External Specification Revision E - I believe this is pre-release documentation for Atari Pilot
Atari Pascal Langauge System Manual - Manual for Atari Pascal Langauge System, released by Atari Program Exchange, catalog number APX-20102.
Atari Computer Game Screenshots - I simply collected these from the Atari 800 Best Game pack. Use them as your screensaver or desktop background.
Computer Palace Catalog Spring 1984 - I discussed this on episode 18 of ANTIC. I love this catalog so much.
I've also scanned and uploaded several more early issues of Creative Computing.