Possible Duplicate:
What's the shebang (#!) in Facebook and new Twitter URLs for?
Hi
I was just wondering what is the use of "!" in urls like this
http://www.facebook.com/profile.php?id=xxxxxxxx&v=wall#!/profile.php?id=yyyyyy&v=wall
I know Facebook uses #(hash) for changing the query string parameters with JavaScript but what is the meaning of exclamation (!), why it is used after # ? We can even work with # only to change the querystring params. Is there any benefit of using ! ? or any other thing is there which I am missing ?