How do I know who is checking my Facebook account

Hi guys,
Facebook is not something new to us. Most of us in the habit of viewing others accounts. I don't know how about you but me personally in the habit of looking in to others accounts. But Is there any method of knowing who have viewed my account in facebook? Do you aware of such kind of a thing. Actually, I'm wondering why Facebook is not coming up with this wonderful feature.
So, guys, do you know any official or unofficial method of checking the persons who are viewing your account? Please do share it here with us..reporter;;:)reporter;;:)