CTRL + T - New Tab Check out for more shortcut keys

https://support.mozilla.org/en-US/kb/keyboard-shortcuts-perform-firefox-tasks-quickly

http://www.mouserunner.com/FF_Shortcuts1Printable.html

Your answer is sad and you should feel bad.

Do you mean that you want to open a copy of the current page in a new Tab?

Easiest to do this with the keyboard is via these two shortcut keys: Alt +D to set focus to the location bar and Alt+ Enter to open the current URL in a new tab. There is no need to release the Alt key in between.

With the mouse you can middle-click the combined reload/stop button on the location bar or hold down the Ctrl key and drag the current tab to a new position on the tab bar.

Thanks for the answer! I can see the problem with my phrase, that's not what I meant. Suppose I'm on page X and that page does not allow for the context menu option "open in a new tab". I can't open many links easily. So I click a link and I'm directed to page Y on the same tab. Now I want to open a new tab with the page X so I can chose another link inside that page and so on. Is there a shortcut for that? It would be extremely useful.

you could try middle-clicking or holding ctrl while clicking links on page X in your example & see if this is making them open in a new tab.

Thanks for the reply. It doesn't seem to work, looks like some sort of flash object. Let me show you an example page:

http://www.promofans.pt/#

Try to open several vouchers.

ok, yes those aren't plain links but some sort of java-scripts - in this case you could middle-click or ctrl-click on the back arrow in the firefox navigation bar when you're on page Y.

Thanks! That's an awesome simple solution, I don't know why I haven't thought of it before. Problem solved! :)