I like to vary my workouts weekly as well. I have a core set of exercises I use, I vary the order I do them as well as the rep ranges/weight used so I don't become stagnant or bored with the workouts. I generally incorporate at least 1 grouping of superseding to each body part worked as well, either at the beginning or end of each workout. This gives several variables to play with so as to avoid plateauing easily. I have never done the whole body workout thing, thinking of trying that once a week to add yet another element into my workouts.
