If you haven't downloaded the free SEO for Firefox Add-on from Aaron Wall of SEO Book, then do it now. It's one of the most helpful and useful Firefox tools I have encountered so far.

With SEO for Firefox, you don't have to go one by one to all the Search Engine Optimization (SEO) tools spread across the web like Overture, Google Adwords Estimator. Wordtracker, Google Suggest, Google Zeitgeist, Goolge Trends, Yahoo Suggest, etc. just to assess the value or popularity of a particular keyword. Just turn on the SEO for Firefox icon located at the status bar at the bottom of the Firefox browser, search Google, and voila, all the relevant links will be produced in the resulting search pages. Just click on these links and you'll get the info you're looking for.