How many gypsies does it ...

Q: How many gypsies does it take to change a lightbulb ?
A: None, but you lose a lot of light bulbs.

http://www.ahajokes.com/lig001.html

How many programmers ...

Q. How many programmers does it take to change a lightbulb?
A. They can't do it, it's a hardware problem

http://www.jokes-db.com/jokes/lightbulbs-jokes

How many type A personalities ...

Q: How many type A personalities does it take to screw in a light bulb?
A: Two. One to screw in the light bulb, and one to tell him he's doing it all wrong

http://www.jokes-db.com/jokes/lightbulbs-jokes

How many idiots does ...

Q: How many idiots does it take to screw in a light bulb?
A: 500, 1 to hold the light bulb and 499 to turn the house
http://www.jokes-db.com/jokes/lightbulbs-jokes

How many Microsoft Engineers ...

Q: How many Microsoft Engineers does it take to change a light bulb?
A: None. They just change the standard to DARK.