Shoulder Stretch by Ferret
From ContactJuggling.org
This stretch will increase your range of motion during extension moves. Arm rolls to cradle, double butterflys , etc. You will feel it mainly in your 'Lats,' and your posterior and middle deltoid, with a small amount of pull on your trapezoid.
I've included a 'still' showing a move that I could not have pulled off with out being stretched and flexible in this regard.
File:Http://www.richshumaker.com/stretch/shoulder/Frotator2.jpg
File:Http://www.richshumaker.com/stretch/shoulder/Frotator3.jpg
File:Http://www.richshumaker.com/stretch/shoulder/LaNoChe 16.jpg