Input source selection

I just received my empeg (I was #1044), and I love it! At the moment (probably more to come later...grin) I have just one suggestion/wish: as I'll probably mainly use the empeg buttons and not the remote, it'd be nice if there was an easy way to cycle through the input sources (empeg, radio, aux).
I noticed that the bottom (hold) button is not yet assigned anything when outside menu mode. Couldn't that be used for this purpose?

Cheers
Daniel