When I added disqus to seanreiser.com I thought it was simple, but one of my tweeps asked for a howto so maybe it wasn't . Also I seem to have had a few hits on from google searching on "disqus drupal". So for the curious here's are the steps I followed.
Caveats:
In all honestly I've done this twice, once the wrong way, and once the proper way.
Here is the Quicker, but Wrong Way
Here is Slightly More Complex, but Correct Way
The major advantage to the proper way is that the comments persist if you change themes.
You may also want to add your rss feed from disqus to your news aggregator and add the block to your sidebar.
Poof you're done. Good Luck!
Share and Enjoy!
/edit: Forgot to mention that you should disable the comment module.
/edit2: added enabling the block, ver 6.2 compatibility and some minor spelling errors, and the blog node type.
/edit3: I'm dropping disqus for now. The reasons are outlined here. I really like disqus and once they add comment importing I'll be back, but for today it's getting in the way of my grand design.
/edit4 I have reenabled Disqus. See this for more information
/edit5 Rob Loach has created a Disqus Module for Drupal 6 here
Sean Reiser, 40, is a developer, technologist, and amateur photographer. Sean has spent the past 20 years as a programmer, system architect and development manager. He is a life long New York resident.
Sean currently serves as the President and Chief Geek Officer of Repair Sense, Inc.. Please go to that site with any professional inquiries.
Sean can be found using a number of social networks. These are the ones he's most active on: