There has been much said, some good and some bad, concerning Alexa's toolbar. This is a tool used in gathering information that will provide a website's Alexa ranking. It is available for Internet Explorer, Firefox and Chrome, the Internet Explorer's version serving as the example for this article.
Please keep in mind this is not a search engine, rather a "companion" designed to provide you with additional information. Yes, you are able to navigate the internet from the toolbar itself, but again it is not a search engine. While navigating the web, the toolbar will provide you not only traffic data pertaining to the website, but contact information of the website as well. You will receive links to other similar websites, and be able to interact with additional users of the toolbar.