A picture is worth a thousand words. A movie is often priceless.
A few days ago my colleague and I were having problems getting warranty service on a machine we support. The problem was that we would see the problem, document the problem, send the machine in, they would sit on it for a few days, declare it fine and send it back. This was getting stupid our client was starting to think that we didn’t know what we were doing. Finally, we struck upon a great way to visibly demonstrate the problem without going down to the repair center and hitting them until they gave us access to their workbench: we faced one of the iMacs in our office towards the problem child PC, opened Quicktime, and told it to record from the iSight camera. Then we demonstrated the problem, with commentary, and emailed the movie to the support team. And their bosses.