In Firefox/Swiftfox 2.0, by default the active tab has a big red "X" beside it. Click on the X and the tab disappears. The disadvantage of this is that one can't delete a tab without making it active. A more desirable behavior would be to have an X in each tab, so you can delete the tab without opening it.
This hack is not mine, so I'll reference Geek to Live, where I found it. What you do is:
- In the address bar of the browser enter about:config
- In the Filter box that appears, enter the string browser.tabs.closeButtons
- Right-click the string that appears, and select Modify
- Change the number to "1" if you want an X in each tab, or to "3" if you want the Firefox 1.5 default behavior (one X, all the way to the right on the tab bar). Experimenting, "0" is the default 2.0 behavior, and "2" is no Xs at all.
The change should take effect as soon as you hit enter.