download from here https://addons.mozilla.org/en-US/firefox/addon/5244 what does it do? features Note 1. you can press F4 or click button on right end of tabbar to bring up all tab preview. or Ctrl-Tab to bring up scroll switcher when you have more than 3 tabs open. 2. This might eventually be added into firefox 3.1. Two pics: all tab preview, and scroll switcher with 3 previews.