If I'm not mistaken, you can capture the fn key as if it were shift, opt, or cmd. On a mountain lion, you can press fn twice to raise the dictation. Even on a lion, you can match fn as a control in some games (see HoN or Heroes of Newerth, where you can use fn as a control key). The problem is that I do not know how and cannot find a way to do this. But, as I said, I'm sure you can use it that way.
I don’t think this will work on windows due to bootcamp drivers, and I really hope someone comes up with a solution for this on bootcamp, since I hate it when the fn-ctrl keys are placed when I am on Windows.
source share