Many of the mid to upper level AV receivers have an RS 232 connection which allows you to connect your computer to the receiver and access advanced functions for setup. While the feature seems primarily intended for custom installesr rather than individuals, it would be a nice way to tweak one's setup. Pioneer's advanced MCACC has this capability.
BUT, how many computers made in the past five years or so have a serial connection? You can try a USB to RS 232 cable and driver (not particularly reliable), but it would seem our friends in the AV industry could wake up and smell the coffee, realize they're incorporating an obsolete technology, and go with USB or (heaven forbid) wireless!