Twitter corpus for Sentiment Analysis from a class (cs224n)at Stanford.
Class page:
https://sites.google.com/site/twittersentimenthelp/for-researchers#Where_is_the_Tweet_corpus_8553
http://www.stanford.edu/~alecmgo/cs224n
A. Ritter, C. Cherry, and B. Dolan. Human Language Technologies: The 2010 Annual Conference of the North American Chapter of the Association for Computational Linguistics, page 172--180. Association for Computational Linguistics, (2010)