This is called an auxiliary port, and it allows users to plug in their smartphones or MP3 players using an audio cable, that way can play their music through their car stereo without the need for CDs.

I hate switching manually, though.<BR><BR>I could just use another mini-to-RCA cable to push my Gamecube audio into the TV tuner's line in, but that's an unnecessary step that would just add noise ...

Mini-Stereo-to-RCA Audio Cable The most common solution used to stream iTunes to an audio receiver is to connect the "Audio Out" or "Headphone" jack from the computer's sound card to the receiver.

This is my first time dabbling with SPDIF/audio extraction (previously have been 3.5mm/RCA/HDMI pretty exclusively) so here I am posting before clicking the buy button on anything.

They're also pretty expensive: $15 for either the 1/8" to RCA or 1/8" to optical adapter, neither of which is very long (though they don't need to be).

The cable connects your iPod, iPhone or iPad to a TV's RCA jacks. It has a 30-pin dock connector that fits into your iPod, a USB connector, and yellow, red and white audio/video RCA connectors.

Asus has even gone to the lengths of including four converters from a 3.5mm audio jack to RCA inputs, for those wanting to output 7.1 surround sound to a dedicated decoder.