That's it, I've read somebody saying "could care less" TWICE today and it's only mid-afternoon. So that is it, I'm going on record saying the next person who uses such bastardised English should be slapped.

For example:

Vista works for me and I could care less

You could care less? Oh so you mean you actually must care about it quite a bit already then? Think about what you're saying buddy, it's couldn't care less!

Meaning it is not possible for you to care any less about subject A.

My own anecdotal take on this is it seems to be growing in frequency and I'm even coming across British people saying it now, at least across the internet. With "could care less" now outnumbering "couldn't care less" on Google.