One of my new favorite sites is Clients From Hell, a self-described "collection of anonymously contributed client horror stories from designers. While they are submitted by designers, I think many people can commiserate.
A few examples:
"We don’t have the resources to support a Web site, so instead, we’d like you to build a spreadsheet that we can email to each individual client."
"Can you show Joanne [client’s secretary] how you designed our business cards. I don’t want to pay you for doing them."
"What would happen if the internet was full?"