A new platform from Kynetx has tools that let developers use customer preferences to add features to Web sites, regardless of the browser.

Phillip Windley, CTO, and Stephen Fulling, CEO of the Utah-based startup, came to Robert Scoble’s home to explain how the platform works and to show us the application in action in this building43 video.

“Our elevator speech is that we provide a development system for building applications that respond to context in the user environment,” Fulling explains in the video.

What does that mean?

It means that customers can get something extra when they come to a Web site. For example, if a AAA subscriber has her or his membership card information installed on PC or mobile device, an extra box with “AAA discounts” will be listed next to companies whose names turn up in a Google search for keywords such as rental cars or hotels.

Another application, through the Minutemen Library Network, alerts members that “this book is available in your local library,” after scanning book titles on a Web site. That application leverages the Jon Udell Library Lookup Project.

“As a developer, you can create the client-side experience” using rules-based platform and Javascript, says Windley.

Kynetx (pronounced Kuh-neh-ticks) is less than two years old. According to the founders, it was bootstrapped for the first year with the money Windley and Fulling got when they sold the small plane they jointly owned.

The Kynetx Developer Conference in November drew 150 people, and the company plans another one in the spring of 2010.

At the developer conference, Doc Searls, senior editor of the Linux Journal and co-author of The Cluetrain Manifesto, said platforms such as Kynetx show the balance of power is shifting.

“As customers gain more power to express their actual intentions, we will move from an economy that places a premium on guesswork – especially advertising, an ‘attention economy’ — to one that places a premium on knowledge that can only come from customers: the customers’ actual intentions. For example, their shopping lists. The result will be an ‘intention economy’ that is a vast improvement on the attention economy,” Searls said.