Ever close a tab in firefox and wish you could just 'undo' it. Well you can, just try this little extention. https://addons.mozilla.org/extensions/moreinfo.php?id=1122
You have had this and never posted it? I got tired of accidently closing a tab and going back through my history looking for it Wish someone had shown me this before.
if you right click on the tabs navigation bar you will see the options. You need to restart firefox after installing for it to work.