Originally Posted by acidzebra
That was me, it is possible, and here is the version for FF 2.x
and here is the version for FF 3.x
Once installed go to the add-on options, then Events > Tab Opening > Open tabs from > and select all cases in which you want a new tab to be opened. It has lots of other features too, you can set tabs to open in the background or foreground, assign custom clicking actions (I like doubleclick to close a tab, for instance), alter appearance of tabs and more.
I knew it out there somewhere!!!