http://incompetech.com/gallimaufry/care_less.html

When one usually states "I could care less", they usually mean "I could not care less". [e.g. "I could care less about linguistics."]

In order for one to "care less" about a subject, they must first care about it somewhat. Saying "I could care less about ... " does indeed imply, nay dictate, that there is some degree of care.

I've put together a handy chart to help visualize...

Thinking about putting this in my signature.