Highlander

When you click a link to an URL that's already open in another tab then you'll switch to that tab instead of actually opening the link. However, some sites using heavy javascript may not work correctly with this, so the extension also offers a whitelist of URLs not affected and the ability to disable the extension at the click of a button.

The whitelist supports wildcards, is the wildcard character and will be interpreted as any character zero or more times.

Requirements:

Windows XP/Vista, Mozilla Firefox 1.5 - 2.0