I setup my Synaptics touchpad left top and bottom corners to close and undo
close tabs in abrowser. So much easier than Ctrl-w and Ctrl-Shift-t.
First install some additional packages
sudo apt-get install xbindkeys-config xdotool
I mapped the corner buttons to some large mouse button numbers to make sure
they don't get mixed up with anything else
synclient LTCornerButton=11
synclient LBCornerButton=12
Then setup xbindkeys daemon to read such mouse buttons. You can do this via a
rc file or using the xbindkeys-config GUI.
key action
b:11 xdotool key ctrl+w
b:12 xdotool key ctrl+shift+t
Then make sure xbindkeys is running and enjoy the newfound ease of browser
use. Of course, the cost is that now you have one more pesky daemon hanging
around. On the other hand, there's no limit to the mischief you can get done
with the xbindkeys+xdotool combo! :)