Firefox possesses a number of incredible hidden functions, which between you and me are quite interesting. This tip allows you to open any link directly in a new tab by simply clicking on it, even if the link is designed to be opened in a new Web page. Of course the middle mouse button provides you with the same result, but this means that you need to remember which links open with a new page and which open on the same page. Not very simple when you are looking around a few sites at once.
Here is how you can activate this function:
1.Open Firefox 1.0 2.In the address bar, type about:config and a new window calle “Filter” will open. 3.In the Filter bar, type browser.tabs.showSingleWindowModePrefs
4- Double click on this variable so that you can change it from False to true.
5- In the menu at the top of the window; click “Tools” and “Options”.
6- In the Advanced section, under the “Navigation by Tabs”, check: Force links tht open in new window to open in:
7- There is nothing left to do then press “OK” to save the changes. The change will be immediate and you can test the functionality by clicking on this Forum link in the left hand menu. You will see that it will open in a new tab or the same tab depending on your choice in step 7.