Chartbeat offers a great realtime view as well. And I really like how they offer an open, transparent look into the offering via data from the businessinsider.com site. Check out Chartbeat's realtime viz on that site's data.
I really like how they pick up Twitter feed as a data source to help augment the overall view. And whether or not you agree on the definitions, the idea of showing reading and writing as engagements is smart too. Nicely done folks...