We also call them wifebeaters, but it isn't exactly politically correct -- and it really bothers me whenever I hear the term. And, as the first post stated, she doesn't think Clark would call it a wifebeater.
I believe that older men tend to wear them as undershirts and younger men tend to wear them as actual shirts -- people like Eminem are shown wearing them all the time.
Personally, since I hate the term wifebeater, I usually call them "tank tops."
- Laura