Url Shortener

Now a days when everyone understands that affiliate links ends with some name or the url is not as it should be,Do you use a url shortner??I use one nice url shortner script ,it hides completely affiliate link,I dont trust anyother url tiny script because they look into the logs,where as these people dont bother about logs, and they declare a very nice privacy policy so i am impressed.

What are you using by the way? and why?