Q: How many neurophysiologists does it take to change a lightbulb?
A: Six. One to remove the old bulb and examine it under the microscope to find out what went wrong, one to blow a tube of glass into the bulb shape, one to coil the tungsten wire filament, one to clean up the metal base of the old bulb, one to operate the vacuum pump to get rid of the air in the bulb and one to apply the glue to seal the new bulb into the old base. The new bulb won't work, of course, but the whole process uses up a lot of expensive equipment and keeps several intelligent people happily employed doing something totally useless.

Q: How many new-agers does it take to change a lightbulb ?
A: Ten. One to actually do it, and nine to stand around going "Hmmm well I don't really mind who does it. I mean, I COULD do it, but of course I woudn't want to impose my will upon anyone else..."
A: Two. One to change it & one to check the new one for bad psychic auras.(and optionally another dozen to perform the dance of the renewal of the light.)
A: Two. One to screw it in and one to check the astrology.
A: Two. One to change it and one to work out whether it'll work in the future.

Q: How many new men does it take to change a lightbulb ?
A: Two. One to change it and one to hold the baby.
A: None. The consensus of opinion appears to be that there is no such thing as a genuine new man, and in any event, the media, who like telling us what we all like, have declared that women don't really go for new men anyway, but instead prefer more masculinity nowadays.

Q: How many new romantics does it take to change a lightbulb ?
A: Two. One to change it and one to say "Wow, what an amazing concept, man !"

Q: How many newsmen does it take to screw in a light bulb?
A: Only one, but he'll tell everybody.

Q: How many nitpicks does it take to change a light bulb?
A: None. They just let someone else change it, then they point out all the mistakes the bulb-changer made!

Q: How many nuclear engineers does it take to change a light bulb?
A: Seven. One to install the new bulb and six to figure out what to do with the old one for the next 10,000 years.