Google recently added a new feature to the define: search command. A query like define:marketing will bring back a list of related keywords like the following:
search engine marketing
Not only is this a great tool for generating lists of related keywords to implement in your search engine optimization strategy, it’s also useful in finding new niches or segments of your market that you may not have considered before now. You can even drill down further by clicking on one of the related keywords. It works very much like Wordtracker but doesn’t come close to being as powerful. But it does give you a glimpse into how Google responds to a specific keyword query.