Sources of classified sentiment data?

Question

I'm looking to train a naive Bayes with some new data sources that haven't been used before. I've already looked at the Lee & Pang corpus of IMDB reviews and the MPQA opinion corpus. I'm looking for new web services that fit the following criteria.

1. Easily Classified - must have a like/dislike or 5 star rating
2. Readily available
3. Pertain to new material (less important than the first two)

Here are some samples I have come up with on my own.

• Etsy API
• Rotten Tomatoes API
• Yelp API

Any other suggestions would be much appreciated =)

Answer 1

Take a look at sentiment140. It has a corpus that you can download and train with. You can easily extend to new tweets.

Answer 2

In Pang&Lee's later work (2008) "Opinion Mining and Sentiment Analysis" here they have a section for publicly available resources. It has links to those corpora.