A routine linux life

Sometime application is hang, and you may not enough expertise to analysis under the hood. Although you can command "ps aux", get the pid/name and kill -9 the pid or killall -9 the name, but there's another convenient way to kill certain window locate/click by mouse. That's "xkill" utility. Left-click can kill the window, right-click can cancel it.

I prefer add the command to panel, I didn't want to open terminal and type "xkill" when desktop already on the hang state :) [UPDATE] I use shortcut key <Super+X> nowadays.

So, right-click panel, "Add to Panel..." and Choose "Custom Application Launcher", then insert "xkill" inside both Name and Command text field. Edit the icon, just open "~/.gnome2/panel2.d/default/launchers/xkill.desktop", edit the "Icon[en_US]=IMAGE_LOCATION" part. Default image is "gnome-panel-launcher".