kick off a custom process from screensaver in Kubuntu

[jippie]

I am running Kubuntu 11.04 and I use the standard "Blank Screen" screensaver. I want to start a command every time the screensaver starts and to stop it when the screensaver stops.

My idea is to copy the "Blank Screen" screensaver and add a couple of my own lines in the source code ...
but I have some trouble finding the correct files.

Anyone any ideas or suggestions how to do this?

[jippie]

while sleep 30; do qdbus org.kde.screensaver /ScreenSaver GetActive; done

Will print 'true' when the screensaver is active, or 'false' when it is inactive.