Voxy - help ESL students learn English...current news and pop culture
http://voxy.com

Dewey Digger - attempt to catalog the web according the the Dewey Decimal System...browsing tool
http://www.deweydigger.com/

Open Culture - "the best free cultural and educational media on the web" [smart youtube channels, free textbooks, intelligent video sites, life changing books, free audio books, free courses, free movies and much more]
http://www.openculture.com/

LibriVox - "acoustical liberation of books in the public domain"...listen to books or volunteer to record books in the public domain
http://librivox.org/