Has anyone written a program that allows the iPod to beep at intervals of your choosing (while music is playing)? Something that would be accessible from one of the menus where you can wheel click the feature on or off, your interval period and rest period, and the volume level of the beep. This would be useful for interval training, e.g. run for 5 minutes, walk for 1, so the iPod would beep at 5 and 1 minute intervals.