the bios swapping of "fn" and "left control" on my x121 had its own problems (it was a bit strange, sometimes the remapped fn key didn't actually behaved like a real control key). so i switched back to the original behavior and learned to deal with it.
a hardware hack would be cool :) letting the fn key electrically do the same thing as the ctrl key and for the rare use of fn use the capslock-key for it :)