A while back, I wrote a post about what appeared to be a causative alternation with the verb wait: I said They wait you in the bookshop. In that post, I said 'sleep doesn't have an object', and this is true: it's the prototypical example linguists use of an intransitive verb (i.e. one that doesn't have an object).
Language is a flexible beast, though, and you can get things like I slept the whole night through, where one might argue that the whole night is an object. But this isn't so clear cut, as you might prefer to say that the whole night through is an adverbial phrase modifying the verb slept, the same as if it was I slept all night or I slept for ages.
However, last week I heard an example where sleep definitely did have an object, and it was the same sort of construction as the wait example in my earlier post. I was on holiday at a folk festival with some friends, including an 11-year-old boy. His mum commented on the fact that he'd only had a short nap, and he said I know but it slept me enough. In this sentence, the subject is it (the nap) and the object is me (i.e. the sleeper). I think that's quite cool.