Still keeping your old NES controller and doesn’t know what to do with it. Learn from this guy from iphonefr.com, who has turned his NES controller into an dock for iPhone and iPod.
It actually doesn’t look like it’d be all that complicated to produce. Clear out the innards of the controller, make a little slit for the iPod connector to fit into, and glue everything in place. Voila, as the French say.