Tints browser tabs with a color specific to the website loaded. It can pick a random color automatically (based on the site's hostname), or it can pick a color based on the site's tab icon.
For more information, see http://labs.mozilla.com/2006/11/chromatabs/
NOTE: may not work with custom themes, or extensions that modify tabs.
NOTE: Won't be updated to work on Firefox 3. FF3 users might want to try out Gary Calpo's "Chromatabs Plus" -- https://addons.mozilla.org/firefox/addon/8004