Day 1 - Chest/biceps
Day 2 - Back/calves
Day 3 - Shoulders/triceps
Day 4 - Quad/Hams
I'm using that split right now, loving it, making some nice gains too...
running it like this:
mon: day 1
tue: day 2
wed : off
thu: day 3
fri: off
sat : day 4
sun: off
repeat...
YUM