The query related:URL will list web pages that are similar to the web page you specify. For instance, [ related:www.microsoft.com/ ] will list web pages that are similar to the Microsoft home page.

Note: Don't include a space between the related: and the web page url.

You can also find similar pages from the "Similar pages" link on Google's main results page, and from the similar selector in the Page-Specific Search area of the Advanced Search page. If you expect to search frequently for similar pages, consider installing a GoogleScout browser button, which scouts for similar pages.