Few things in life are more pleasurable than stopping a telemarketer dead in their tracks. Telling a cable or satellite TV telemarketer that you don't own a TV is one way. And during the next few instants in which they scan their script to find a possible response you have the perfect window of time to interject a polite "thanks for calling" and hang up. Technically I DO own a TV, however it is relegated to monitor duties for a DVD player and Sony Playstation in my daughters room. It's not that I am against TV, I enjoy watching sports or sitcoms or whatever with friends. It's just that I don't miss it when It's not around. It's really like a deeply jaded apathy toward the whole media platform. Writer strike? Tell somebody who cares bud. I do however enjoy watching movies and listening to music, and while I am not an audiophile per say, laptop and computer speakers in my budget range are tinny at best.

     Getting audio from your Linux machine into your home theater or stereo system is not that hard, though there are a myriad of connection issues that can complicate the task. I am neither qualified nor inclined to argue which type of connection is the best, and of course whatever you choose needs to be supported by your sound card and your theater system, but I decided on "digital coax" aka "spdif". From what I can tell both are technical terms that mean "wickedly overpriced single RCA cable" but I will defer you to the 15 year old expert Best Buy employee to get the real skinny. Since neither my laptop nor my desktop at the time I set this up had the ability to do digital out (required for "digital coax") I opted for a USB sound card. I actually received one as a gift but if you have to pick one up yourself the Sound Blaster Live USB card is inexpensive, supported in Linux, and has acceptable sound quality.  Take note that the term "acceptable sound quality" is coming from someone who can remember spending the entirety of several concerts within an arms reach of speakers turned up so loud they could loosen your stool.  Regardless the investment on hardware is 15 bucks for the cable, and 35-ish for the USB sound card. Not bad.

    Driver support for USB sound is a feature of ALSA, so depending on your Linux distro or configuration you will need to either build the modules or check dmesg after plugging the card in to see if it was recognized.

usbcore: registered new interface driver snd-usb-audio

The two modules required are snd-usb-audio and snd-usb-lib.  ALSA sets up a handy file in /proc to show us the details of the sound cards the system sees. Mine looks like this:

jason@jackass ~# cat /proc/asound/cards
  0 [External       ]: USB-Audio - SB Live! 24-bit External
                       Creative Technology SB Live! 24-bit External at
                       usb-0000:00:1f.4-1, full speed

If you have a sound card setup already the USB sound card will probably show up as entry number 1 below the built in card, though sometimes they are inexplicably reversed if the USB card is present when the machine is booted. I have not taken the time to determine why that is but it happens rarely. Unless you work some asoundrc file magic to rename the devices you have to note which number the USB sound card is then use this to setup your favorite ALSA friendly sound applications. XMMS has a convenient dropdown with all the enabled cards listed, but the notation to do it by hand is not hard. In the above case the USB card is ALSA device "hw:0,0". If it was the second card listed it would be "hw:1,0". The only other sound producing software I use is mplayer, which has a dialog to configure the ALSA paramaters including the device name. 

     That's really all there is to it. I use the speaker controls on the theater system to switch between two channel for music and Dolby surround for movies. I seriously doubt that the surround sound signal is being processed in exactly the correct way but there is no mistaking that its being split up reasonably well when the doorbell rings in a movie and I get up and start moving toward the door before I realize it. My USB sound card has been happily pumping out audio at nearly a constant rate for several years now and it was not expensive, pretty easy to figure out, and really makes a big difference in the way things sound.