Light Bulb - New Yorker

Q: How many New Yorkers does it take to screw in a light bulb?
A: One. What are you -- stupid?

Light Bulb - Publishers

Q: How many publishers does it take to screw in a light bulb?
A: Three. One to screw it in. Two to hold down the author.

Light Bulb - City Planners

Q: How many city planners does it take to screw in a light bulb?
A: Six - four to write an extensive study recommending a three-way 100/200/250 watt light bulb, one to write an article in the newspaper praising the study, and one to put in a 10 watt blub instead.