Rated 3 out of 5 stars

For Duplicate this tab:
One thing that's missing from this port over is an icon for the add-ons screen (even a default icon of a jigsaw piece)

By removing the following line from the install.rdf the default icon shows up under 3.6
<em:iconURL>chrome://duplicatethistab/skin/icons/duplicatethistab-icon-small.jpg</em:iconURL>
Note Firefox 4.0b10 still has no icon shown. The file referenced above does exist at the above location though.

This review is for a previous version of the add-on (1.1).  This user has other reviews of this add-on.