A keyword generator that is available freely for use
Keywords can be used on many end: Site title, description tag, body text, important tags (h1, h2, etc ...)
Google has introduced a free service that can allow you to target more precisely, either on your site, or on competitors websites
Note from Google
Important: The Keyword Tool automatically identifies a list of queries made on the search engine Google, in connection with the keyword you entered. The terms listed you are not advised or recommended and Google can not guarantee that these keywords will improve your campaign performance. We also reserve the right to disapprove any new keywords you selected.
You are solely responsible for the keywords you select and you must ensure that their use does not legislation or affect the rights of third parties, including the law of trademarks and unfair competition. Before selecting a keyword, you should verify that it is not a trademarked term.