Extracting hidden Shortend url

Many of u know abt shortend url being used now a day.
So what abt them...are they secure??
we cannot abt the real url and if any risk is there on the webpage.
There are websites
It help u know about the real link behind the scenes
Extract Url
http://www.urlvoid.com/extract-url/

Untiny
http://www.untiny.me/

Realize URL
http://dev-ehren.appspot.com/realize_url/index.html

Preview URL
http://www.prevurl.com/

Bye
Thanks to me and sujay