Middle Mouse Button, Again

After I found about Opening Link in New Tab using mouse middle button, later I also found that the middle button can be used to close a tab. It really helps, cause now I don't have to hardly aim the little "x" button to close a tab.
It works on Mozilla Firefox 3+ & Internet Explorer 7+.

Doh, it's getting interesting... I think I'm going to optimize the mouse middle button usage. hehe
Googling for some information about it right now....=p