For albums that have a '/' in their title, the SoundUnwound link is broken:
http://musicbrainz.org/release/c826fc14-223e-4d14-98fe-013a66dcebed leads to http://www.soundunwound.com/music/Ruckspin%20&%20Quark/Hornz%202008%20/%20Sunshine/mb:c826fc14-223e-4d14-98fe-013a66dcebed

EDIT by hrglgrmpf: This is true not only for albums, but also for artists, e.g. "Phantom/Ghost":
http://musicbrainz.org/artist/bb5ba090-bc09-42c4-9cd7-a800d1434965
leads to
http://www.soundunwound.com/music/Phantom/Ghost/mb:bb5ba090-bc09-42c4-9cd7-a800d1434965
http://www.soundunwound.com/music/Phantom%2FGhost/mb:bb5ba090-bc09-42c4-9cd7-a800d1434965
(both broken)
http://www.soundunwound.com/music/Phantom-Ghost/mb:bb5ba090-bc09-42c4-9cd7-a800d1434965
(works)