Indeed, I beleive the human ego is outside of nature(though I prefer non-natural to unnatural as the latter has slightly pejorative connotations).
As far as the things we do are concerned, its tricky. I was responding to jonnyyukon who said that our actions are worse than that of a bear, for instance. I think the reason for that is simply our technology. Our technology, like our arts, is something we create and make. Since our minds, which could be considered the mold of our actions, are non-natural, yet the "clay" in which we create technology and art(the physical world) is natural, you have somewhat of an in-between when it commes to our actions being natural or non-natural. The dead sea scrolls(for example) are a creation of man, they mean something to the mind of humans, and yet they are part of the physical world too.