Q: How many usability people does it take to change a light bulb?

A: Four and a random third person. One to complain about the bulb, one to complain about the light-holder, one to complain about the way the bulb has to be changed and one to write a note stating how the next person entering the room should change the light-holder, which bulb to use and how it should be done.

Stolen from WebWord.