SpinEdge
Spins the interior edge connecting the verts in a quad.
Works when in Editable Poly base object - Edge mode in max 5 -6 and 7. Works when in Edit Poly modifier Edge mode in max 7. Exactly ONE edge should be selected for the script to work. Open Edges are obviously not supported. You can press and hold SHIFT while clicking the icon to reverse the direction of the spinning. (works best when the script is placed as button on a toolbar).
Inspired by this thread on cgtalk...