If you haven’t come across them Despair Inc offer parodies of those motivational posters you see up on the office wall of a David Brent type. Some are very funny indeed.
You can also create your own, so here is mine. This is what someone said to someone I know recently when discussing a project. If I wasn’t moving to an open plan, I’d have it up on my wall. (image – TPorter2006 http://www.flickr.com/photos/tporter2/1392077364/).