I was frustrated by the thought of having to buy a home theater receiver just so I could decode the
AC3 output of my satellite receiver. I found the following item on Ebay and it does the trick nicely for under $20.
Cyberhome CH-SRD600R 5.1 surround sound headphones come with a converter that takes either the
coaxial or optical input and gives you analog audio out. Don't let the funky headphone connector scare you; the mini-plug part is the same as any MP3 player and accepts a mini-to-RCA adapter nicely.
I paid $10 + s&h for mine and it works great for
PBS, Create, and other AC3 channels.
That's my contribution to the effort!