If you want to know where the technology revolution is headed next -- and what red-blooded, investment-crazed American does not? -- a good place to start is the office of Greg Papadopoulos here in Silicon Valley.

It's a small room, located in a nondescript low-rise building. In that respect, it's like most of the offices around here, where the billion-dollar ideas are hatched. And to say that Papadopoulos is casually dressed is generous -- he's wearing running shoes, a knit shirt and baggy paints that look unmarked by the old-fashioned technology known as "ironing." But what comes out of Papadopoulos's mouth is rich stuff, indeed.

Papadopoulos, 41, is the chief technology officer of Sun Microsystems -- the company that understood better than any of its big competitors where the tech boom of the 1990s was heading. Sun summed up what has become conventional wisdom with this simple formulation: The network IS the computer. In other words, computer applications would move from the stand-alone PC on your desktop into the big computers that run networks and the Internet.

Because Sun got it right in the mid-1990s (while its competitor Microsoft was often getting it wrong), the company now has enormous momentum as it builds out the technology ideas it pioneered -- such as open standards, network computing and the Java programming language.

So what will the future look like? From what Papadopoulos says, computing power will be so pervasive and reliable that it will seem more like the central nervous system -- and less like a higher brain function. That is to say, it will feel more like breathing (which is automatic) and less like thinking (which is a strain and often misfires.)

The computers powering this world will be incredibly complex, but to users, they will feel as simple as a portable phone (which, Papadopoulos says, will be to the next decade what the PC was to the past decade).

Papadopoulos last week described four big ideas that are driving Sun's research teams as they prepare this next generation of the technology revolution:

"Scalability." As the Internet scales up to handle connections with what will soon be a billion devices, it has to become much more reliable. Unless the technology has the instant availability and security of a telephone dial tone, consumers won't trust it to handle their essential transactions -- from banking to medical care.

To meet these demands, Sun is designing computers that will be much faster. Today the company's biggest computers link together 64 processors, but Papadopoulos says that five years from now, they'll handle 1,000 to 10,000 processors. And these processors will communicate instantaneously -- thanks to much more widespread use of fiber optics in computer interfaces and internal design.

"The speeds are blistering," says Papadopoulos. "We're absolutely pushing the laws of physics. The speed of light is the limiting factor."

Processing speed will allow the computer brains of the network to handle the torrent of information that will soon be racing through broadband connections, also at near light-speed. If Sun's big computers, known as servers, aren't fast and reliable, the system will crash, but Papadopoulos thinks Sun can keep up.

Convergence of Internet and telephony. Driving this transformation will be a new generation of wireless phones (known as 3G, for "Third Generation") being developed mostly in Europe and Japan, which will transmit data at high speeds. Services will flow invisibly and seemingly effortlessly to these portable phones. If you want to know the weather, for example, you'll dial a number, and a local weather map will appear on the screen of your portable phone.

Papadopoulos predicts that by 2003, a billion of these 3G phones will be in use -- radically increasing the demand for Internet services. Sun is working with the phone makers -- companies such as Ericsson, Nokia, NTT and Motorola -- to develop a slimmed-down version of Java software that will make it all work.

All video, all the time. Once we have big, fast pipes to connect us with the Internet, they can deliver content that will be more like video. Papadopoulos predicts that in this video-rich world, we'll each have what amounts to our own TV channel.

Sun's offices already have a little of this "me-TV" technology -- a system the company calls "Sun Ray." Papadopoulos plugs an ID card into a reader and his personal desktop appears on a screen. He walks down the hall and plugs the smartcard into CEO Scott McNealy's machine and that same desktop, which Sun calls a "Hot Desk," appears. This video desktop, or "Webtop," can be accessed from anywhere there's a screen and a reader.

Sensors and Sensibility. Papadopoulos predicts that we're heading into a world where tiny sensors will be built into every appliance and device -- all connected by wireless telephony to the network. We'll have smart water pipes that know the location of a leak and smart refrigerators that know when you're low on milk (and order more from the grocery store).

At this point, Papadopoulos's vision begins to sound like science fiction -- a world where computers surround us, silently communicating where we are and what we need. That forecast may sound far-fetched, but when it comes to technology, recent history suggests that you shouldn't bet against Sun.