This is a hilarious illustration of the ways that Microsoft Powerpoint is being misused:

The Gettysburg Powerpoint Presentation

Also see:

Edward Tufte: Powerpoint is Evil

Tufte has been on this rant for some time. The most useful point I take from this is to be skeptical of the information presented in Powerpoint - not to be sucked in by the perception of legitimacy that Powerpoint provides. It can obscure high quality information, and give false credibility to worthless information.