A while ago, Data Wrangling Blog published a list of Datasets available on the Web. The list has been updated, adding up to 400 datasets, plus Video Lectures, Seminars, and Talks.
About Manos
I work at ILPS, University of Amsterdam. My research revolves around mining social media, tracking content, and predicting user behavior. My interests lie in the field of Information Retrieval, and query modeling, but also in predictive analytics, and recommender systems (with a touch of Physics whenever possible).