Egomaniac Light Bulb

Q: How many egomaniac does it take to screw in a light bulb?
A: One, because the egomaniac can hold the bulb, and the rest of the world will naturally revolve around him.

USS Enterprise Crewmembers Lightbulb

Q: How many members of the USS Enterprise does it take to change a light bulb?
A: Six.  Scotty to get on the intercom when the light goes out and say, "I canna do it, Cap'n!".  Spock to tell Kirk he is proceeding illogically.  McCoy to say "Dammit, Jim -- I'm a doctor not an electrician!!"  Kirk to screw it in and two red-shirt security officers to die in the process.

Californian Bulb

Q: How many Californians does it take to screw in a lightbulb?
A: Five - one to screw it in and four to sit in the hot tub and discuss the environmental impact.