(FORTUNE Magazine) – So the first thing you learn about the Internet from studying America's Most Admired Companies is that you don't have to be on the bleeding edge of the Web to be admired. Or even the leading edge. Call up Warren Buffett, the planet's second-richest man and CEO of Berkshire Hathaway (No. 7), and he says, "If you want to talk to me about the Internet, you must be desperate!" Not that he isn't up to speed on infotech. He's been carrying a cell phone for going on two months now. E-commerce? Go to berkshirehathaway.com and click on the Berkshire Activewear button. If you like the pictures of those folks wearing shirts with Berkshire's fistful-of-dollars logo, click on the order button. Fill in the form. Print it out. Put it in an envelope and mail it to Omaha. Your order will be shipped in two to four weeks.

Actually the big picture isn't as bad as that. Buffett's Geico insurance company will give you an online rate quote for car insurance (regulations make it tough to sell insurance over the Net), and his See's candy company sells chocolates through a Website that's reasonably efficient. In general, Buffett says, "I'm strongly in favor of all our businesses using the Internet." He's a heavy user himself, spending ten to 12 hours a week online playing bridge, and he calls up endless SEC filings of companies he's thinking of investing in. No question, though, that Berkshire falls at the low end of any scale rating innovative uses of the Net. At the other end is Microsoft (No. 2), which doesn't just use the Net; it's basing its whole business on it. In between are the rest of the top companies, which in all divide neatly into five tech outfits and five more-traditional businesses. In each group you'll find companies doing impressive, surprising Net-based things.

Start logically with General Electric, America's most admired corporation by a mile for the third year in a row. A lot is happening with e-commerce at GE, though 14 months ago hardly anything was. The explanation is simple: Jack Welch got religion. He used to have a reputation as a non-e-guy who refused to have a PC in his office for years, although everyone else had one. But when his eyes finally opened, he developed the passion of the convert, declaring at the beginning of 1999 that e-business would be a major GE initiative. Welch's initiatives are not flavors of the month; in 19 years as CEO he has announced four. And he is, to put it politely, demanding. So within days things started happening across all 20 of GE's key businesses.

GE's plastics distribution business, Polymerland, didn't have an e-commerce team in January 1999. It had a Website doing a mere $10,000 of business a week. Today the e-commerce team is 30 people doing $2 million of business a day online; by year-end, they figure on about $4 million. By itself that isn't as impressive as it seems. The savings from online orders--Polymerland receives 200,000 fewer phone calls a year--are nice but not revolutionary. What changes everything is what comes next. Polymerland wants to use the Net to bind customers to it more tightly. Customers, like injection molders that melt plastic nuggets and turn them into casings for such things as Apple iMacs and Nokia cell phones, hold inventory in big silos. So Polymerland has installed sensors in the silos to reorder when volume gets low. Could a competitor supplant this technology? Of course. That's why speed is critical. Like any company serious about e-commerce, Polymerland wants to attract as many e-customers as possible as fast as it can, then make it easier every day for them to stick around.

That's similar to the strategy at GE Power Systems, even though practically no one buys electricity-generating turbines online. They can be as big as a house and cost millions of dollars; customers kind of like to talk to someone first. Power Systems nonetheless has an e-commerce strategy--again, launched like a rocket early last year--intended to bear-hug customers. One element is the so-called turbine optimizer, a Web-based tool that enables the operator of any GE turbine to compare its performance with that of other turbines of the same model everywhere in the world. The tool shows the operator how to improve the turbine's performance and how much money that improvement would be worth, and, naturally, it lets the operator schedule a service call to make the improvement happen. Yes, GE could do all this before, but it took weeks.

Power Systems also creates what it calls customer Web centers, sites exclusively for individual customers, designed with their help, to give them all kinds of useful information. Not all of it will be about GE turbines, but some of it will be, and with luck the customer will find it so useful that he won't want to do without. Even if not many companies buy turbines online, they buy (or rent) other stuff: services, portable power-generation equipment, and parts. Power Systems got $17 million via the Net last year; this year it's figuring on $1.5 billion to $2 billion.

What GE demonstrates is not how extensively a company can use the Net--others are doing much more--but how far a non-infotech company can go in 12 months from a virtual standing start. For state-of-the-art Net exploitation, you need to look at some of the tech companies on the list.

For all you read about consumer e-commerce, the largest volumes and most dramatic efficiencies are on the back end, in the business-to-business world of the supply chain. For instance, Dell (No. 3) sells huge volumes online, recently about $35 million a day, but that's a mixed blessing; Dell also likes you to order by phone so those human order takers can sell you things you didn't know you needed.

Dell's true gains come from the extraordinary integration of its system into the supply chain. A single order can trigger all kinds of automatic component reorders; it schedules production and shipping as well. Dell also creates company-specific Web pages to give each customer extensive data about its orders. These strategies are impressive, though not unique. But now Dell has developed software to integrate its Web assistance into a customer's own enterprise resource planning (ERP) software. Thus, when a customer orders from Dell, he not only triggers a response within Dell and its suppliers, he also engages his own company's systems: approvals, budgets, inventories. Switching to another computer supplier becomes a real pain.

One component vendor digitally entangled with Dell is Intel (No. 8). Like Dell, it has committed huge resources to Web-based systems that manage inventory. Why? Hardly any business, except maybe fresh fish, loses inventory value faster than infotech. So Intel not only keeps moment-by-moment track of its inventories, it also shares this information with customers, who return the favor with data about their own inventories. Says Intel vp Sean Maloney: "Our Web-based tools enable a single, Internet-based image of the supply chain. That sounds like a small thing, but it's enormously significant. It takes hundreds of millions of dollars of excess inventory out of the supply chain."

For pure gee-whiz use of the Net, Cisco (No. 4) is hard to beat. It makes the routers and other specialized computers that power the Internet. Manufacturers generally require lots of capital, but Cisco uses little because it outsources most of its manufacturing to 35 contractors worldwide, which ship products in Cisco boxes directly to customers. That helps generate stunning returns on capital but poses a potential problem: quality. The solution lies in the fact that Cisco products are purely electronic and thus can be tested anywhere on earth. After a contractor makes a product, he connects it to one of 700 Cisco servers worldwide, all networked to headquarters in San Jose. If the test shows that the product is the wrong one or that it doesn't work, the interlinked system won't print a shipping label. Without a shipping label, the system won't generate an invoice. And without an invoice, the contractor won't be paid.

The most sophisticated infotech company among the nontech members of the Most Admired is Wal-Mart (No. 5). It famously possesses the best information system in retailing, a satellite-powered network that relays data from every store every day, automatically commanding a network of suppliers. With the best back end in any business, it has signed on with the best front end, AOL, as an e-commerce partner. That's quite a contrast with the other big retailer on the list, Home Depot (No. 9). At homedepot.com you can't buy a thing except a gift card to spend at the stores. The company plans to offer all its products on the Web in certain parts of the country at midyear, gradually expanding nationwide. But, hey, they're still most admired. Same with Southwest Airlines (No. 6), which sells tickets online like all other airlines, but hasn't done more than keep up.

So no, you don't have to be totally wired to be admired. At least not this year. But consider: Of the ten most admired companies, Cisco wouldn't exist but for the Internet. Microsoft is banking its strategy on the Net. Dell and Intel virtually run on it, and the business of Lucent (No. 10) consists increasingly of helping customers use the Net. Wal-Mart annihilates competitors, in large part with superior infotech. GE, late to the party, has dived in. That's seven of the ten making major bets--or betting everything--on the Net. You have to wonder how much longer before it's all of them.

REPORTER ASSOCIATE Ahmad Diba