A simple rotation of the sandbag (or kettlebell, if no sandbag is available) while descending into a reverse lunge will challenge your strength and core stability in the transverse plane.
When you add in the power of a swing, what you wind up with is a really cool explosive movement – the swing requires decelerating the implement at the bottom of the movement before you explode from the lead leg into hip and knee extension.
The nutrition and training info is top notch and so are the writers. I really enjoy Eric Cressey, Mike Robertson, Dan John, Alwyn Cosgrove, Charles Staley, Chad Waterbury, and Christian Thibaudeau. I've read much of what they've written.
Since I've started writing for the T-Nation, I've gotten 100's of e-mails asking me varying questions about the rotator cuff and its many somewhat magical qualities. While it may not be as cool as big quads or a great set of guns, a well-developed rotator cuff is sexy in its own, injury-free kind of way.