Most PC users are a lot like suburban drivers. They want the equivalent of a sport-utility vehicle even if they only surf the Net a bit and check E-mail. Computers get cheaper every day -- so why not? Yet some frugal entrepreneurs see buying power computing for everyone on staff as a waste of money, space, and maintenance and training time.

Tech companies have taken the hint. There is a growing array of devices that perform a limited range of computing tasks on the market now, from phones with screens and keyboards that let you surf the Net and use E-mail to network computers with limited functions.

Some, like the screen phones, are novel now but won't be for long if big telecom equipment makers such as Nortel and Alcatel, which are promoting them, have their way. Others, like the networked terminals known as "thin clients," have a checkered past. Descendants of the old "dumb" terminals without processors that ran off big companies' mainframes, thin clients drew a lot of attention a few years ago when such biggies as Oracle, Sun Microsystems, and IBM promoted them as The Next Big Thing. They never caught on -- partly because PC prices dropped so much. Still, IBM is pushing the technology again as an economical, low-maintenance option for small businesses with networks.

MIND-BOGGLING COMPLEXITY. The fact is, PC alternatives can be a risky bet in many ways. Yes, they're cheaper than full-fledged PCs, which generally cost at least $1,000 for most small-business needs. And the mind-boggling complexity of even common software programs has technology makers promoting a future full of simpler, specialized information processors, from "smart" household appliances to TV-based Internet access. The problem for small businesses is this: If you miscalculate and need the PCs after all, the economical move becomes a waste of money instead.

Optometrist Jerry Sude, a partner at an Akron (Ohio) clinic with 30 employees, made the switch to a more modest technology because his full-service, underused PC actually slowed him down. He ditched it six months ago for a $300 screen phone that lets him get and send E-mail, surf, and hear phone messages. Sude, who spends most of his day seeing patients, used his PC for little else. It was overkill, he says.

The device Sude uses, the iPhone from InfoGear, connects to the Internet over a standard phone line and automatically checks for E-mail from his Internet service provider, then downloads it. Sude can't download information from the Web or store it on his iPhone. That doesn't bother him. He's entranced with such features as a blinking light that lets him know if he has E-mail -- like an answering machine. "It saves me two, three, or four minutes each time I walk into my office between patients," says Sude. "The blinking light tells me if I have mail so I don't have to boot up a PC. That really adds up during the course of the day."

Two years ago, Bob Prescott, owner of the 20-employee Co-Op Bookstore in Baton Rouge, La., looked at what his staffers needed to do their jobs and also concluded that he didn't need to give everyone on staff full computing capacity. He started switching from PCs to thin-client terminals purchased from IBM, which typically cost less than $500 a piece. He now has five PCs and eight thin clients.

Sometimes called network computers, thin clients are like PCs without hard or floppy drives, CD-ROMs, sound cards, central processors, or many other components of stand-alone computers. That's why they're thin -- about the thickness of the college textbooks Prescott sells. The user has a monitor, keyboard, and a mouse. The thin client gets its processing capability from the server, a powerful computer at the center of most networks, to which it's connected. Access to applications and the Internet comes from the server, not the PC's hard drive.

Prescott allocated them based on store logistics. For example, anyone who uses Books in Print, the publishing-industry bible, which comes on a CD-ROM still has a PC. He also installed two thin clients in the store so students can look up their required course books in a database. The shift doesn't shortchange the rest of the staff, he says: They can still do word processing, work on spread sheets, and search the Web.

EXPENSIVE TO INSTALL. What are the big advantages of thin clients, other than price? Putting all applications on the server lets technical staff control who can do what on their computers. No problems caused by personal software from home, for example. That makes it easier to prevent employees from using their business PCs for recreational purposes. And upgrading software is done once, at the server, for all the connected computers. The downside: You need somebody with network expertise -- in-house or a consultant -- to install thin clients. That can be expensive. Another negative, when the server goes down, so do all the terminals. PC users can still work, even if the server isn't functioning. And, of course, if more people need disk or CD-ROM drives to do their work, the thin clients won't do.

Nonetheless, Prescott insists the thin client is a better investment than PCs for his needs right now. Thin clients are "easier to learn, there's no support to speak of, and they're cheap," Prescott says. He says he has no plans to go back to PCs.

Sude is similarly satisfied. His iPhone is the only one in his clinic, but he says he's planning to install them for the other doctors: "There are four of us doctors, and I'm sick of them using mine."

Buying a PC alternative can have greater or lesser implications for your company's technology strategy: Buying a screen phone is a lighter choice than a thin-client system. The trick is visualizing your company's future needs. One comforting thought: With the rapid obsolescence of technology, you can't be stuck too long with the wrong decision.

David Haskin in Madison, Wis.