Cameramanbob,
Describing plugs and receptacles as "polarized" is a common and accepted terminology, but I think the word "polarized" not the best choice. Maybe a better description would be "keyed".
As pointed out by other posters, AC power has no polarity like direct current does.
What AC power has, and so receptacles and plugs have, is a high potential conductor/ slot (the hot) and a low potential conductor/slot (the neutral). The hot is at high voltage relative to earth potential and the neutral is lower voltage (close to earth potential in a correctly designed, built, and maintained system). Keep in mind that the current flowing in the neutral is the same as that flowing in the hot...and it's the current that kills you.
So it's safer to "key" the slots in the receptacle and the blades of the plug, so that the hot conductor will not be attached to the shell of a lampholder, and so that the hot conductor is switched.
So I think that your question comes up because of a mild misuse of the word "polarized". Is this clear as mud?
Cliff