HideTab is a Firefox add-on which will allow you to hide individual tabs in Firefox, this can come in pretty useful, when you may want to keep pages open but do not want them to take a extra tab in the browser.
It can also be used to hide NSFW content from your boss and colleagues.
Once you have installed the add-on, you will see a tiny icon in the status bar, that will display all the hidden tabs. Individual tabs can be hidden by either right clicking the tab and selecting hide tab, or using the shortkey key Ctrl + Q.
You can use a hotkey Alt + Q to hide all the open tabs and open a default tab, which can be configured by changing the HideTab options. To unhide the tabs just use the Ctrl + Alt + Q hotkey.
If there are hidden tabs, the color or HideTab icon will automatically change to red.