Just came across a website the other day and thought we could use this guy's information on scrotum stretching. He seems like he knows what he's doing and it looks like he's done a lot of research. Anyways here's the link for the site. Here you can learn more about stretching that sack.
http://www.secretleather.com/jarod.johansen/
http://www.secretleather.com/jarod.johansen/