LinkedIn Companion for Firefox
Described as the Facebook of the business world, LinkedIn allows you to network with others in your profession. If you're a fan of the site then the official LinkedIn Companion for Firefox extension is a must.
The add-on does three main things. The first is to add a button beneath the bookmarks toolbar that displays a menu, showing shortcuts to various sections of the LinkedIn Web site. It also allows you to share the Web page you're browsing on your LinkedIn profile, and tracks recently-viewed profiles.
Secondly, the extension adds LinkedIn entries to the Firefox search box so you can quickly search both the LinkedIn site and also its jobs section.
Note: This link takes you to the add-on's page at Mozilla.org, where you can automatically install the file into your Firefox browser.