The new think tank summit, Think20, was in line with the proliferation of forums within the G20, including the B20 (for business), L20 (for labor unions), Y20 (for young people), and the SC20 (for civil society organizations).
Here is a video of the Think20 summary session, organized by COMEXI (no translation available)
Here is a YouTube video of Stanley Foundation's David Shorr discussing his participation in the Think20 meeting. Here is a piece Mr. Shorr wrote for World Politics Review on Think20.
Here is another YouTube video on "main contributions of think tanks to the G20 Summit" with Stewart Patrick (CFR), Thomas Bernes (The Centre of International Governance Innovation), and Colin Bradford (Brookings).
A full list of the 23 participants and their biographies can be found here. And here is a statement made at the conclusion of Think20.
Here is the final Think20 Report to the G20 Sherpas.
I wonder if the G8 will start the "Think8."
By the way, if you share a healthy skepticism about international organizations, you may want to check out this Financial Times (FT) piece by Gideon Rachman on how to write about international organizations.
He wrote a satirical generic column on how reporters write about international institutions. Here is the mention is has of think tanks:
The story was given further padding by a study from an ambulance-chasing Washington think-tank, which warned that it would continue to convene media conference calls until its quixotic and politically suicidal plan to ameliorate whatever crisis was gathering had been given respectful though substantially undeserved attention.