Opinion Mining/Sentiment Analysis resources

We're actually trying to integrate Opinion Mining techniques into some of our future products, and I've been reading a lot about Opinion Mining and I found the survey "Opinion Mining and Sentiment Analysis" by Bo Pang and Lillian Lee a really valuable resource, as it contains an extensive bibliography, publicly available datasets and lexical resources, etc.

Another interesting source of contents has been WOMSA workshop (1st Workshop on Opinion Mining and Sentiment Analysis), held in November 2009, with some up-to-date applications.

I also found interesting that Evri API that offer some sentiment-related details about some entities that are indexed in Evri.

I'm convinced we'll see a lot of Opinion Mining powered applications and services during the next years, it's a really interesting field in terms of its applications in marketing, social media...