Google AdWords: Keyword Tool

From the 'Keyword Variations' tab, input keyword phrases and variations and Google's tool will provide a listing of keyword phrases, corresponding numbers of searches, their popularity, AdWords competitor popularity, and much more, to help with your AdWords campaign. You can select keywords to add to your AdWords bids, too. You can also download the results in .csv format (comma-separated value, a common database format for spreadsheet programs, including Microsoft Excel and others). In addition, within the 'Site-Related Keywords' tab, you can input a Webpage URL to find keywords related to the content on a particular page, too. Helpful indeed. See also Google AdWords Keyword Tool - A Useful tool for AdSense Publishers via ProBlogger.net for screenshots and information about how this tool works.