Not sure if this has been discussed before as working, but I know I saw that people wanted this function to work. What function is it you ask?

Well, assigning Mobile Network options to a right or left side convenience key so as to be able to quickly adjust 2G/3G settings. If you are using the latest iteration OS and concomitantly use the Precision AT&T theme, you'll get an icon for Mobile Network in the Settings folder. As such, any iconed item is assignable to a convenience key. Assign, and ta-da!