Light Bulb - GLC Workers

Q: How many GLC workers does it take to change a lightbulb ?
A: Four. One to do it and three to go round putting up posters announcing that the GLC, working for London, is going to change the lightbulb.

Tech Writers to Change Lightbulb

Q: How many tech writers does it take to change a lightbulb?
A: None: It should be obvious to an intelligent user.

Light Bulb - Smokers

Q: How many smokers does it take to change a lightbulb?
A: At least five. If they all light up together the lightbulb will do so too.