Even this, though, is merely an appetizer for an idea, still without concrete embodiment, which SRI calls the “digital companion.” Much like Microsoft’s statistically based filters, it envisions agents that adapt to human needs-only on a much larger scale, as the OAA facilitator idea is extended to include personalized agents that will stay with people for years or even decades. Just as a good secretary learns a boss’s preferences and even comes to anticipate his or her needs, so will a digital companion serve its human masters.

“Think of it as a PDA (personal digital assistant) on steroids,” relates SRI’s Mark. “It is your assistant, it is your broker to this set of services and devices available in the network.” Your companion, he says, will authenticate your identity and pay your bills. It will make travel arrangements based on your preferences–and will even see to it that the rental car’s radio is set to your desires. Can’t remember the wine you drank at a restaurant last week? Just ask your companion: It will reference your bills and maybe the restaurant’s wine list to find out. In short, says Mark, a digital companion will be a person’s “universal remote for the world.”

The ubiquitous-computing vision remains in many senses just that: a vision. Beyond the immense technological challenges of building a public utility infrastructure and creating digital companions loom mind-staggering issues that run from programming for the networked world to real fears of Big Brother-like invasions of privacy. Jeffrey Kephart, who heads the Agents and Emerging Phenomena group at IBM’s Thomas J. Watson Research Center in Hawthorne, N.Y., even foresees the billions of agents that will soon be out there setting prices, bidding and making purchasing decisions as an economic wild card with potentially immense ramifications. “What we’re talking about is the introduction into the economy of a new economic species,” he says. “Heretofore we’ve only had humans.” He’s working to model and study the dynamics of such a system-and divine ways to avoid price wars and generally help prevent things from getting out of control.

No one yet knows the solution to such puzzles-nor are the answers even evident in today’s mishmash of efforts. All of which means that truly ubiquitous computing could still be decades off.

Steadily, though, the major pieces seem to be coming together, giving rise to a view among some in the industry that the new day is at hand. SRI’s Mark is one such optimist. So, too, is Jim Waldo, chief engineer of Sun’s Jini effort, which, by removing many of the barriers that exist between systems based on different operating systems and languages, marks a big step toward the dream.

“My feeling about the whole ubiquitous computing thing is it’s getting to the point of almost being a supersaturated solution-and at some point, the crystal’s going to form. And when it does, it’s going to happen really fast,” Waldo asserts. “There’s going to be lots of this base work. It’s going to be going nowhere-and all of a sudden it’s just going to be there.”