NASA Techs to Change Lightbulb

Q: How many NASA technicians does it take to change a lightbulb?
A: Seventy, and they plan it for two weeks and when they finally get around to it the weather's bad so they postpone it till next week. The lightbulb costs three million dollars.

Romanians to Change Lightbulb

Q: How many Romanians does it take to change a lightbulb?
A: None. Ceaucescu restricted them to use only one 40 watt bulb per family to save electricity.

Light Bulb - Canadians

Q: How many Canadians does it take to change a lightbulb?
A: Four. One to spray green paint onto the bulb so noone bashes it with a big stick, one to change it, one to suggest they all roll a log down a hill to celebrate, and one to invite all the others round to his log cabin so they can all watch his moose moult.