From the horse’s mouth… boy this makes keyword research a lot easier and quicker… I recommend using this folks.
This new version of the Keyword Tool combines the functionality of the Keyword Tool and the Search-based Keyword Tool. This means you’ll get keyword ideas based on keywords you enter, your website content, and user searches – all in one place. Also new is the ability to search by any combination of a keyword, website/URL, or category – instead of having to perform each of these searches separately. Additionally, you’ll be able to see all match types for a keyword at the same time to help you compare statistics for each match type. When you’ve got your final keyword list together, you can download a selected keyword, all keyword results in the table, or all keywords (for certain queries).