APESplit (Advanced Parametric EdgeLoop Split) created by Oliver Beardsley is a modelers must have tool. I should say, was. It hasn’t been updated for Maya 6 or 7 yet. This is a plea Oliver! If you see this, do us all a favor and update APESplit for Maya 6 & 7. At least let us download the old version so we can try to update it ourselves.
I would consider this to be much more versatile than MJPolyTools edgeloops. It allows you to pull your edgeloops in and out based on surface normal directions and by default will follow the existing curvature of your poly flow. It works excellently with Quads and can even perform complicated splits along selected edges.
Small description here:
For any type of poly modeling this tool will drastically improve workflow and speed.