The Center on Animal Liberation Affairs was co-founded by Dr. Steven Best, Associate Professor of Philosophy & Humanities at the University of Texas at El Paso.
From their website:
As the first scholarly center dedicated to philosophical discussion on animal liberation, CALA strives to advance the study, research, and dialogue of the principles and practices of animal rights and animal liberation.
They publish an interdisciplinary online journal very much worth checking out:
http://www.cala-online.org/Journal/TOC.htm I just found this website tonight and haven't looked through it much yet, although it appears to be an extensive collection of animal rights related essays / works by various philosophers, both modern and earlierl
http://www.animal-rights-library.com/ Some more links:
http://www.planetvegan.org/ethics/default.asp