Watch the Open String Banjo Scale online guitar lesson by Gareth Pearson from Travis, Atkins & Reed Guidebook
This is a cool and different approach to playing scales. The trick is to allow every second note to ring along with its previous note. The right hand is playing a banjo roll pattern across the strings vertically, while the left hand is doing the intense stretching in order to fret the correct notes. Don't forget to alter your posture in order to make the stretches more natural.