If you are looking for a Firefox add-on that allows you to display Google PageRank, Alexa rank, Compete ranking and SEOmoz Linkscape mozRank anywhere in your browser, then this one’s for you: Quirk Search Status Firefox Add-on. Quirk Search Status is designed for the highly specialized needs of search engine marketers (SEM). Quirk Search Status toolbar provides extensive search-related information about a site, all conveniently displayed in one discreet and compact toolbar. This combined search-related information means you can view not only the link importance of a site (according to Google and Linkscape), but also its traffic importance (according to Alexa and Compete), so providing a balanced view of site efficacy. I use this toolbar all the time to determine whether a site has enough traffic to warrant accepting a joint venture proposal.