Check out these sites for more information on groups working on Access to Knowledge (A2K):

• Civil Society Coalition: http://www.civilsocietycoalition.org
• Computer Professionals for Social Responsibility: http://www.cpsr.org
• Consumer Project on Technology: http://www.cptech.org
• Doctors Without Borders' Access to Medicine campaign: http://www.accessmed-msf.org
• Downhill Battle: http://www.downhillbattle.org
• Electronic Frontier Foundation: http://www.eff.org
• Free Software Foundation: http://www.fsf.org (USA) | http://www.fsfeurope.org (Europe)
• Future of Music: http://www.futureofmusic.org
• Grain.org: http://www.grain.org
• International Centre for Trade and Sustainable Development: http://www.ictsd.org/
• IP Justice:  http://ipjustice.org
• Open Access News blog: http://www.earlham.edu/~peters/fos/fosblog.html
• Public Knowledge: http://www.publicknowledge.org
• Third World Network: http://www.twnside.org.sg
• EDRI Digital Civil Rights in Europe: http://www.edri.org/
• TACD Trans Atlantic Consumer Dialogue http://www.tacd.org/
• INDICARE The INformed DIalogue about Consumer Acceptability of DRM  Solutions in Europe: http://www.indicare.org/
• World Blind Union: http://www.worldblindunion.org/
• ALA American Library Association: http://www.ala.org/
• AALL American Association of Law Libraries: http://www.aallnet.org/
• Consumers International: http://www.consumersinternational.org/HomePage.asp?NodeID=89645

Also, feel free to add additional links by posting in the comments section below.