Viv is listening to one of our too-few classical music CDs and I idly googled for free sources of more classical performances, with interesting results that inspired a Metafilter post:

Classic Cat describes itself as "the free classical music directory," and offers links to 3rd-party-hosted downloadable recordings, sliced and diced by hits, composer, performer, and more. There are active fora. Given the old-school look of the site, I was surprised not to find it in my repost search.