I just compiled this list of resources for a colleague and thought it might be helpful for others:
Nonprofit Commons – http://www.nonprofitcommons.org
Weekly meetings (Friday at 8:30 am PST) for their community of 32 nonprofit offices and other orgs, manged by TechSoup.org.
Commonwealth Island – http://commonwealth.wikispaces.com
A natural-themed home for progressive advocacy groups, especially environmental groups. FOR’s virtual office is there as well as ACLU, Code Pink, and the Prison Dharma Network.
A Better World in Second Life – http://www.levjoy.com/blog/betterworld
Short documentary by a grad student exploring the potential for social change in Second Life.
SL Netroots – http://rootscampsl.org
Progressive activist group with weekly meetups (noon PST Thursdays) on Progressive Island in Second Life. I am the facilitator and co-founder of this group.
MacArthur Foundation, Digital Media and Learning – http://www.digitallearning.macfound.org & http://spotlight.macfound.org
“five-year, $50 million digital media and learning initiative … to help determine how digital technologies are changing the way young people learn, play, socialize, and participate in civic life”
Daily meditations for global peace – http://viviennecassavetesblog.vox.com/library/post/global-meditation-for-peace-update.html
Interesting discussion of faith-based groups in SL and how to deal with “decency” issues: http://www.socialsignal.com/blog/rob-cottingham/matters-of-taste-when-second-life-gets-too-explicit
What did I miss?