I've been using Spotify for a few weeks, it scrobbles by last.fm and lets me listen to loads of old country blues and classical whilst at work. It allows collaborative mixes - so if you are using spotify and have some recommendations/suggestions feel free to put them on and I'll give them a try. Spotify doesn't have complete coverage so I don't expect it to replace people emailing mp3s any time soon, but there are some great songs. I've started just by adding a few songs with the word lonesome in the title.
The Lonesome playlist
All About Collaborative Playlists