I found it works for running. After you have a two month streak going, you really don't want to miss a day. You find you make the rest of your life fit around it.
This principle is why many Lisp hackers fail to make good web sites or applications. Lisp programming can lead to days and weeks of fun programming, so that you break the chain of doing less-fun but important programming. Sometimes the improvement users want most involves non-fun programming. You really have to push yourself to implement it instead of procrastinating by coding something more fun but less desired.
I can imagine using multiple colors for various tasks on a single board. I might try this. I use something close to GTD, with a flat text file. I really need a PDA though.