I was watching Guy Fieri's "Diners..." show and he was in Chicago at a BBQ place. The guy he was interviewing won 3rd place in Memphis in May, and here are the ingredients that went in his rub:
Crushed red pepper
Equal parts black and white pepper
He used a mustard slather on top of the pork: yellow mustard + beer + pepper + salt + italian salad dressing solids only + apple juice + some of the above rub
Sounds pretty damn good to me!