A scale.
or
1,000,001: One to change the bulb and 1,000,000 to rebuild civilization to the point where they need light bulbs again.
or
A garbage truck.
or
None: A `Real Woman' would have plenty of real men around to do it.
or
To get to the baaaaarber shop
or
1,622. One to tell the original joke, and the rest to submit give some minor variation of it! For example:
or