Really! There is a sensor of some sort in Beijing that is measuring the quality of the air in that city and broadcasting the information via Twitter. (BeijingAir (BeijingAir) on Twitter)
In some ways, this is a set back from a webcam. But in other ways, it is better, because now someone could take this data and do some analysis of it over time, or do a mashup with it.
I expect we’ll see more things like this soon.
Smart People I Know 