Use canonical urls to improve SEO
Today there's a lot of talk about duplicate content and SEO. What happens to your blog when a search engine crawls it and discovers the same blog post exists in a specific category archive, and on an own page? What happens to your e-commerce website when you've got products tagged with more than one tag? Duplicate content.
This creates problems for search engines - but there's a simple solution - canonical urls.
Canonical urls to the rescue
Canonical urls, or canonicalization as it also is called, helps you decide what address should be the standard address for specific content on your website. What you want to do is to start using a new link rel attribute: canonical.
Put the new link rel attribute in <head> and provide the default url for the specific content, like this:
<link rel="canonical" href="http://blog.dileno.com/archive/200907/going-english/" />
Read more about canonical urls in Google's webmaster blog.