The Tweet-o-Meter machine, currently on display at the British Library, measures the number of tweets coming in per minute from nine major cities around the world. (The cities being monitored are Shanghai, Tokyo, Hong Kong, San Francisco, New York, Sydney, New Delhi, Moscow and London.) Part of the Growing Knowledge Exhibition, which is meant to "spark a debate on the future of research," the Tweet-o-Meter will remain on display until July 16, 2011.

A digital version of the Tweet-o-Meter can be found on the website of the Center for Advanced Spatial Analysis at University College London.

Via ReadWriteWeb.