In Chrome, if I want to duplicate the current page in a new tab, I highlight the address bar and click Alt+Enter. What's the equivalent keyboard shortcut for Firefox?
I'm currently on a Mac with Firefox 14.0.1. I will test on Windows and Ubuntu later to see if it works there.
Opt-Return
(i.e.Alt-Enter
in Mac terminology) works like a charm on OS X Mountain Lion with Firefox 12.