If you have a scroll wheel mouse, just mouse over any part of the tab you want to close and click the center button (wheel) and that tab will close, even if your not focused on that tab's window. Works in Firefox and IE.
Using the right mouse button, a drop down menu will appear, giving you several options, you can close the tab your currently on, close all the other tabs at once, or refresh the tab your on or all of them.
Holding the CTRL key and pressing W will close the tab your focused on, leaving the others open.
thanks... now to get my video's working.