There is also the facePathSplit tool. This script can be found in the bonus game plug-in at Alias|Wavefront's site. It basically is the same thing as the split poly tool, only it will split your object down the middle all the way around with one click. Recommended only for use on simple, cube-like shapes unless you really know how to use it.

Here is the actual script alone for easy download. And once you have it, here's how you get it to work:
1) Open the Script Editor.
2) Choose File>Source Script.
3) Browse for the script, press "ok."
4) type facePathSplit into the Script Editor or command line and press enter. All script commands are CaSe SeNsItIvE I believe.

At this point, you will have noticed that the bottom section of your tool box has a blank tool in it. This is the facePathSplit tool.

5) Select your object, then select the blank box in the toolbox.
6) Click on your object and view the results.