Just like the lamb lying down with lion, but the big three search engines came together for a rare joint effort to announce the launch of a new feature that will help ease the world's duplicate content problems. The new feature, called the <link> tag tells the search engines what version of the URL is the correct one to want index.
The link tag goes in the <head> section of the page of looks like this:
<link rel="canonical" href="http://www.somerandomsite.com/hot-dogs" />
The search engines have been doing a pretty good job figuring out the right URL when people use redirects properly, but it's not always easy to get it right--especially when we build these nutty sites with 50 different URLs pulling up the same content. This change should help a lot of webmasters sleep easier knowing that their proper, canonical URL will be indexed and given all the link juice it deserves. I look at it like a page by page sitemap to tell the search engines what URL to index.
Official blog posts about the new link / canonical tag:
Coverage on other blogs: