TODO: Organize these somehow
Organize by usage? (classification, recommendation etc.)

theinfo

http://www.cs.technion.ac.il/~gabr/resources/data/ne_datasets.html

4 Universities Data Set

20Newsgroups

UniProt
Netflix Prize/Dataset
WordNet
DBPedia
UCI Machine Learning Repo

http://mloss.org/community/blog/2008/sep/19/data-sources/

http://www.icwsm.org/2009/data/

Book usage and recommendation data from the University of Huddersfield

http://ece.ut.ac.ir/DBRG/Hamshahri/ (Approximately 160k categorized docs)
There is a newer beta verson here: http://ece.ut.ac.ir/DBRG/Hamshahri/ham2/ (Approximately 320k categorized docs)