My office buddy was in the habit of walking away without locking his machine so we did a couple things to it over a few days.
Created a really crappy drawing of the him using paint.exe with a bubble saying “I love project”, where project is the dead-horse being beaten. Then we set it as his desktop and sent that email out to everyone in the company using his email.
A Week or two later he didn’t log out agian so I wrote an app that would logout a user from windows every 2 min. And it went something like this.
Login, work, logout. Huh?
Login, work, logout. Expletive.
Login, work, logout. Plethora of Expletives.
Uncontrollable laughter ensues.
He locks his machine now