At home I still have my christmas one up:
Me in a ball.
My work desktop features animated gifs. There the thought police are also computer illiterate so daren't tell you have a standardised PC look.
Belvedere, I like the idea of quoting a picture.
OK - how about a thread where each successive person posts a screenshot of the post before they replied to it. A tube of CDfreaks fora into the distance. Kekeke.