Is this possible to temporary switch off action of automatically turn off computer.

I usually want to turn computer after some time, but some times in unexpected cases, I have to quick leave my work, but I don't have time looking in the system settings.

It will be great if it took the form of a button/icon on some panel.

This is example how to turn off this action http://sourceforge.net/p/kshutdown/wiki/Kiosk/, but how to hook it into icon and switch, not turn off action?

in widgets is there a lock/logout widget? there's also a kshutdown widget for scheduling shutdowns