iGuidance Screen Switching
I have been trying to figgure this out from all different angles as well. I wrote a fast and crude script to determine if iGuidance is notifing you of an upcoming turn. This is done by looking for the "Olive Green" top bar that show's up when a turn is approaching. Right now it will only work if the iGuidnace screen is on top, and showing. Thus, the only thing it could be used for currently is pausing winamp or something.
I THOUGHT there was a way to "go behind" the current window, and check for Pixel color, but I haven't found a way as of yet. I THINK that's how iGMon worked. If that can be worked out, this may be a sollution.
here is a script EDIT: Read 4 posts down, There is a MUCH improved version to try out now :)