"There's a robot snake that slithers along on wheels, and actually snaps out to bite your hand when the infrared sensor sees you there. You can shake a smartphone to make it hiss and strike, or tilt to use the phone's inertial sensors to steer."
The London Eye, the tallest Ferris wheel in all of Europe and a renowned U.K. tourist destination that sits right off the river Thames. Tweets lighting up the Eye are based on the feelings extrapolated from the millions of Twitter messages flowing through the stream.