The New York Times is currently featuring a story about sensor networks in the wild.

What they've got, in fact, are a bunch of Always-On testbeds.

For instance. A sensor network checks the condition of grapes and the soil they're growing in, letting the grower know when to water, and when to harvest to get the best wine.

That is a great Always-On application. How many of those can you sell, maybe 1,000?

But what if, instead of building a big sensor network you built a little one, along with a simple drip irrigation system.

Know how many of those you can sell? You can sell millions. Start with golf courses, move on to schools and office parks, and watch sales zoom with water prices. Just follow Moore's Law and within two years you've got a consumer product, the whole set-up available at a do it yourself shop for maybe $300.

ON World of San Diego is quoted in this story as estimating the sensor network market at $7-10 billion by 2010. (The illustration here is from the Times story. The logo above is from ON World.)

They're way low. Or, if they're accurate, they're looking at maybe the midway point in the hockey stick.

Sensors are not bound by the limits of the wired world. They can rest anywhere -- both on your body and in the environment. Depending on how quickly they update the network, and the user interface linked to them, they can be simple or very complex.

This is the World of Always On. It's real.