In past few years, several prominent US magazines and newspapers have begun to offer their extensive archives online and on DVD. In some cases, this includes material dating back to the 1850s. Collectively it is an incredible record of recent human history, the ideas, people, and events that have shaped our country and world as recorded by writers, photographers, editors, illustrators, advertisers, and designers who lived through those times. Here are some of most notable of those archives:
Harper's Magazine offers their entire archive online, from 1850 to 2008. Most of it is only available to the magazine's subscribers. Associate editor Paul Ford talks about how Harper's archive came to be.
The NY Times provides their entire archive online, most of it for free. Most of the stories from 1923 to 1986 are available for a small fee. The Times briefly launched an interface for browsing their archive called TimesMachine but withdrew it soon after launch.
Time Magazine has their entire archive online for free, from 1923 to the present.
Sports Illustrated has all their issues online for free, dating back to 1954.
The Atlantic Monthly offers all their articles since Nov 1995 and a growing number from their archive dating back to 1857 for free. For a small fee, most of the rest of their articles are available as well, although those from Jan 1964 - Sept 1992 are not.
The Washington Post has archives going back to 1877. Looks like most of it is for pay.
The New Yorker has free archives on their site going back to 2001, although only some of the articles are included. All of their articles, dating back to 1925, are available on The Complete New Yorker DVD set for $40.
Rolling Stone offers some of their archive online but the entire archive (from 1967 to 2007) is available as a 4-DVD set for $79.
Mad Magazine released a 2-DVD set of every issue of the magazine from 1952-2006.
And more to come...old media is slowly figuring out that more content equals more traffic, sometimes much more traffic.
Update: Nature has their entire archive online, dating back to 1869. (thx, gavin)
David Carr wrote an article for the NY Times about the Washington Post's recent decision to close down comments on their blog when one of their threads turned ugly. As the article points out, the issue of web sites having problems dealing with feedback (particularly published feedback like comments) is not localized to mainstream media publications:
Mickey Kaus of kausfiles.com, which does not carry comments, said that "the world is crying out for the jerk-zapper," although he added that he thought that The Washington Post's Web site overreacted. BoingBoing, a heavily trafficked "directory of wonderful things," shut down its comments section last year. "We took a lot of heat over it," said Xeni Jardin, a founder of the site. "But until we are able to come up with a better comments system - most of what is out there is too crude - it is not worth the trouble.
If you're wondering why the comments on kottke.org aren't on more often, this is the reason. This site is a one-person operation and even though I work on it full-time, I don't have the throughput to manage a lot of threads. Comment gardening (as I call it) is hard work if you want to maintain an appropriate level of discourse. And as Xeni said, the current technological and user experience solutions suck. Approved commenting, sign-in to comment, Slashdot-like comment moderation...they all have their problems.
As an experiment back in October, I opened the comments on all threads on kottke.org for a little over a week. During that time, I kept track of my comment gardening duties, basically everything I did to keep those threads clear of trolling, flaming, off-topic comments, and the like. The only thing I didn't record was how many times per day I checked for activity in all the open threads -- every 15-30 minutes or so while I was awake (~8am to midnight) -- because I would have been too busy recording the checking to actually do the checking. At one point, I had almost 60 simultaneous threads open and was spending half my day keeping up with all of them.
After more than a week, I stopped recording everything...even though most of the threads were still open and the comments, flames, trolls, and spam kept pouring in. But the resulting document will still give you some idea of what's involved with opening comments on kottke.org. I would love better tools to deal with this because I enjoy having comments open on the site and so do my readers. But for now, I think it's a better use of my time to focus on other aspects of the site and open comments when I feel a particular post would benefit from them.
 You can't imagine the reasons I've heard about why comments are off on kottke.org. Most of them are variations on the theme of: "All the big bloggers have their comments turned off because they're too stuck-up and self-important to care what their readers have to say, those arrogant bastards. They can't stand people disagreeing with them." And so on.