Dreadhead - in addition to the Grand Pecking Order released by Oysterhead, many legal, live recordings are freely available. While the sound quality isn't as nice as the album version, the live shows are great as well. If you use bit torrent, many live shows are available at http://bt.etree.org, and for Oysterhead specifically, use this link:
http://bt.etree.org/?searches=&cat=132
http://bt.etree.org/?searches=&cat=132