Financially-Relevant Data

As buy-side and sell-side firms continually search for new ways to gain insight into the markets, they are turning to an ever-widening array of data: new forms of financial data (prices, fundamentals, etc) and also non-financial data (weather, parking lot occupancy, etc) that are financially-relevant.  I am working with a number of clients who are looking for new "alternative" sources of financial and financially-relevant data.  If you have a novel data set that you believe should be of interest to financial firms, please let me know about it.