Firefox 4 uses a combined Stop/Reload/Go button that is positioned at the right end of the location bar.
During the page load process it shows as a Stop button and after the loading has finished the button is changed to a Reload button.
If you type in the location bar then that button becomes a Go button.
You can middle-click that Reload button to duplicate the current tab to a new tab.

I don't think you understood the question, but thanks for taking the time to respond.

Firefox still has this feature, you just click and hold the back button or the forward button, depending on whether you want to go back or forward.

Use one of these methods to open the tab history list:

• Right click on the Back or Forward button
• Hold down the left mouse button on the enabled Back or Forward button until the list opens

You can look at this extension:

• Backward Forward History Dropdown: https://addons.mozilla.org/firefox/addon/backforedrop/

Thanks NoriMori and cor-el. This was exactly the feature I was looking for.

You're welcome.

Sorry that I posted the wrong answer the first time.

No worries. Take care.

Thanks all, I was also looking for that feature, the right click works great

...I've learned something new.., thanks ^^