(FORTUNE Magazine) – When you make an airline reservation, why can't the computer take care of setting up the whole trip? The computer knows you need transportation to and from your home airport, and a hotel room and rental car at your destination. The computer knows who you are and which kind of meal and seat you prefer on the airplane, not to mention your credit card number, and the rental-car company and hotel you prefer. Why can't the system just take care of setting up the whole trip at once? Indeed, why can't the system dispatch a shuttle van to your house to get you to the airport an hour before the airplane leaves? And, if the airplane is late, adjust the van's schedule and then deliver an update to your cellular phone or pager? Heck, why couldn't it even display the shuttle van's current location on a dynamic map on your own Web page?

Those are questions I've heard asked by Nobel laureate Arno Penzias, a partner in our firm who was once the chief scientist for Bell Labs. He's somewhat plaintive in his questioning. He seems to consider it an affront that travel-service companies haven't yet figured out how to do all that.

Given how much I travel, I have to agree with him. All the information needed to do it is stored on computers. All those computers are now connected, one way or another, in a ubiquitous computing system. The global-positioning technology exists to track the shuttles, manage their dispatch, and record their location. So what's stopping us from using those computers to vastly simplify our incredibly complicated modern lives?

The answer is time. We've only now gotten to the point where this kind of integration among different computer systems is possible. Since we're still human, it takes us a while to figure out how to design the systems and then how to make them work.

Fine. Having acknowledged that, I must insist that now, finally, it is time. It is time to deliver these services.

It is time not just for services that streamline travel. It's time for customized services to emerge from the worlds of banking and personal finance. It is time for services to emerge from many different industries, services that employ our personal data to simplify anything in our lives that involves information. I call this E-service--customized services that are delivered electronically through the World Wide Web.

Fortunately, a new category of company is emerging to provide such E-services. All these companies start with the idea that you can integrate computer systems and harness them to provide services that were previously not possible. They are not merely companies providing outsourced computer services, a category that has existed for some time. Instead, these are companies designing services that can't be provided either within a company or as a commercial service to consumers without the existence of a ubiquitous, high-speed, easy-to-use network like the World Wide Web.

A while back I wrote a column about a new credit card called NextCard. This is an example of E-service in practice today. Anybody older than 21 can remember what it was like to apply for a credit card in the old days--in, say, 1996: In tiny little print, you had to fill out double-sided forms with lots of tiny boxes supposed to encompass your financial history, including the account number for every account or loan you'd had for the past ten years, your addresses for the past ten years, and a detailed accounting of how exactly you derived your current income. Now you can apply for a NextCard Visa credit card online in 30 seconds: All you provide is your name, address, Social Security number, annual income, and a few minor details. NextCard's owner has figured out how to integrate its Website with the databases of the major credit bureaus, so that in just seconds NextCard identifies who you are, looks up your current credit balances, does a calculation based on that information, and actually suggests which balances to transfer in order to get the lowest rate on NextCard. No need to go into your shoebox filing system to find all your various account numbers. (Of course, applying for a NextCard doesn't mean you'll get approved. Several of my richest venture-capital and entrepreneur friends say their applications were rejected in those very same 30 seconds.)

NextCard is a fine example of E-service, and it's good news for both consumers and investors. The company's E-service is a key part of the value provided by this new business. And that's the really interesting thing for an investor like me: E-services can be the core value behind entirely new businesses.

E-service has started to become a theme in how I am investing our firm's money. One of the first E-service companies I invested in is Netcentives, which figured out how to link the computer systems of airlines' frequent-flier programs with the systems of Web-based merchants: Those online shops now offer their customers frequent-flier miles as an incentive. Another of our portfolio companies, Visto, gives you a way to synchronize your personal data--appointments, contacts, bookmarks, E-mail messages--with a Web server so that you can look at that data from any computer connected to the Web. I've even checked out companies that help you buy utility services for the lowest possible price. I'm working hard to find an online bank that can provide an array of financial E-services, although I have to admit that my existing bank, Wells Fargo, is moving fast in that direction. In fact, financial services are the one industry already starting to provide E-service.

Of course, I'm not the only really smart investor out there. I'd have to say that Benchmark Partners beat me to the punch by investing $5 million in eBay--a kind of electronic flea market that has been wildly successful. Benchmark invested about a year ago, and its stake is now probably worth somewhere around $400 million. eBay is particularly appropriate in this context, because without that ever present network known as the Web, the company wouldn't even exist.

Actually, we have another company in our portfolio--Financial Engines--that takes the concept of E-service to its logical conclusion by providing an integrated system for offering investment advice to employees about their 401(k) portfolios and lets them act on the advice with cool graphical controls.

There are plenty of other E-service outfits. (Check out www.freeshop.com and www.catalogcity.com for two other companies experimenting with this model.) As standards emerge for integrating activity among various kinds of companies and as our understanding of how to integrate computer systems improves, you'll begin to see dramatic differences in the ways that companies provide services. And I'll let you know as soon as I get that phone call announcing the imminent arrival of the airport shuttle, just in time to make my plane.

STEWART ALSOP is a general partner with venture capital firm New Enterprise Associates. Except as noted, neither he nor his partnership has a financial interest in companies mentioned. Alsop may be reached at stewart_alsop@fortunemail.com; the column may be bookmarked at www.fortune.com/technology/alsop/