I generally take my CDs (old or new purchases) and record them in a lossless format for use over my Sonos system. However, I have purchased some digital albums from Concord Records, which sells DRM-free MP3s recorded at 320 kbps and has a line of digital-only releases for out-of-print recordings. Not perfect, but at least it gives me access to music not readily available otherwise. For my iPod Touch, I use some compression because of limited storage capacity.