Use the Working Pivot mode! Also, the Sub-obj Pivot script from FunkyBunnies helps a lot :) http://www.funkybunnies3d.com/tools.php I'd recommend you assigning a keyboard key for "Affect Pivot Only Mode Toggle" too.
You might try going to http://www.funkybunnies3d.com/tools.php and check out the "Sub-Obj Pivot" script. It lets you quickly move the working pivot to any subobject. Bound to a hotkey, it really speeds up stuff like this.