What a contribution he made to the world!
Democracy Now has an extensive archive of Zinn's talks [2] to add to what Patel posted. But seriously, you can find his work everywhere. A beacon for hope, curious and determined to uncover and share truth. He will be missed.
Links:
[1] http://rajpatel.org/2010/01/27/howard-zinn-1922-2010/
[2] http://www.democracynow.org/tags/howard_zinn