Washingtonpost.com and CJRDaily both added "Bookmark with del.icio.us" buttons on their article templates today.  At the bottom of every article is a link that spawns a popup for users to save this article with del.icio.us and to add tags to help them find this article later.  These are the first major media properties that I'm aware of to adopt the bookmark button.  (Are there others?)

I think it's critical for publishers to think about ways to enable their users to utilize content in more ways.  This bookmark button is one of the lightweight user actions that will expose content in new ways to mashups, RSS feeds, recommendations sytems, and all the other new discovery tools that people are using more and more in addition to search engines.  Even if only a small percentage of a site's users act on content in social ways, there will be positive effects that emerge from those actions.

Anybody can add the del.icio.us button to their site.  There are instructions for doing that here, and the bizdev contact at Yahoo! who can help is John Klem (jklem@yahoo-inc.com).