SenseWeb is composed of three basic parts: sensors (or data-collecting units), Microsoft's database indexing scheme that sorts through the information, and the online map that lets users interact with the data. The sensors used in the project can vary in form and function, and can include thermometers, light sensors, cameras, and restaurant computers. SenseWeb puts baseline sensor information, such as location and function, into a database that's searchable by location and type of sensor information.

Then, if someone wants to check traffic conditions along a stretch of highway, for instance, the database will direct queries to cameras ("Web cams") located along the route -- and an image of traffic shows up on the map.

In order for people with sensors -- from researchers at universities to a private citizen with a Web cam -- to participate in SenseWeb, Nath says, they would have to be able to upload data to the Internet and provide information to the Microsoft group about their sensor, such as latitude, longitude, and the type of data it provides (for example, gas prices, temperature, or video).

One challenge for the SenseWeb project will be making the different types of information pulled into its database consistent enough to analyze and sort, says Samuel Madden, professor of computer science at MIT. For instance, there would need to be standard units for temperatures. "As soon as you start integrating all this data, you can imagine that weird things will happen," he says. "It's really a challenge to build tools that work with generic data and to come up with a way that anyone can publish their information."

Another, more fundamental hurdle for the SenseWeb project, Nath says, is getting people to register their sensors and sign on to the free program. Gas stations or restaurants may not even know about the project, or may not have an efficient way to pass along their data.

Therefore, in coming months, the Microsoft group will extend SenseWeb to universities that have already deployed sensors for other projects. In addition, the team is talking to a company that has sensors on parking spots, which, if integrated into Live Local, could help people find available parking more easily, he says.

For now, though, SenseWeb and Live Local are separate projects, according to Nath. The Live Local team "really loves this technology," he says, but right now "what's missing is the actual data."