Find out other domain names of websiteSome webmasters register a lot of domain names related to their main site in order to be at the top in search engine results for more keywords. This is achieved by using domain names containing keywords. Such "satelite" domains either serve content from main site using scripts or use IFRAME html tag to include the pages of main site.
To find out other domain names of some website, just enter website name into the entry, and hit OK. This is a more reliable method than listing all domains registed by your competitors since private domain registration can hide those domains.
By finding out other domain names of the website, you can find missing keywords you forgot to optimize your site for.