Some people claim that "couldn't care less" and "could care less" mean the same thing. While the intention behind both is undoubtedly the same, the two phrases are not the same.
1) Couldn't care less = "I am incapable of caring less about _________ than I do right now."
2) Could care less = "I don't care much about __________, but I do maintain a sliver of interest in the subject."