I discovered this accidentally. Some of you might already know this. Anyways, before i knew this trick, tabs were annoying to close; you need to move your mouse wayyyy to the right to click that "X". Well If you have a 3 button mouse (left click, middle scroller thingy, right click), you can click on the tab using the Middle Scroller and the tab closes. Also, if you click on a hyperlink with the middle scroller, it will open in a new tab.