But Sony is a volume company, and a few million units here and there of a relatively low-priced, low-margin product isn't enough to keep senior management interested. That brings up two questions: Why isn't the PDA market much larger than it is, and what will Sony do next?

The answer to the first is easy-for most people, the price/performance of PDAs is poor. Processor cycles aren't the issue here; I'm talking about what the product does and how easy it is to use. PDAs, especially of the Windows CE variety, have very good levels of functionality but are painfully difficult to use. I have owned a good number of PDAs of this type over the years, and each has had real usability problems in both configuration and application.

I hate reading manuals, but with PDAs I have to. It would seem that this problem could be solved if only someone would sit down and look at how real people actually use these products. Try to configure a wireless-LAN adapter for a PDA and you'll quickly see what I mean. My mom isn't going to buy one, and there's not a big enough market for Sony, and many others, unless she does.

Which brings us to Sony's next move. Sony is also part of Sony Ericsson, the perpetually struggling manufacturer of some pretty good cell phones. I think the future is clearly in more-functional handsets, which fall into the personal-communicator class of products-essentially, combined PDA/cell phones. And this is where Sony needs to go, as users pare the number of devices they carry.

Of course, today's PDA phones are a bit clunky, being too large-and too expensive-for many. Sony's challenge, then, is to build communicators with the right mix of size, function, cost and, most important, usability. It's a challenge for the company's competitors as well, but I think eventually someone will get it right.

Craig J. Mathias is principal of Farpoint Group (Ashland, Mass.).