Please people, it's 'couldn't care less' not 'could care less'. If you say 'could care less' it means that you care a little and it's possible to care even less than you already care. 'Couldn't care less' means you don't care at all.

For example, "I couldn't care less if all priests were castrated as part of their entry to the priesthood" or "I couldn't care less if Sue Uteck lost her voice to laryngitis". Nope not a care in the world. In fact you care so little, you couldn't care any less than you already do, which you don't.

Therefore, 'couldn't care less'. Unless, of course, you do care a little and you could care less which would make the above point moot. —Ah fuck it. Who cares?