For years the infotech industry has been predicting that wireless handheld devices would soon be as versatile as desktop computers. But the best handhelds on the market still don't come with enough memory to store the average Web browser, let alone Microsoft Office.

Fortunately, they may not have to. A technique called "application streaming" could allow Palm Pilots and cell phones connected to wireless networks to run large applications without storing the software locally. It's an updated version of the old mainframe network design, with programs residing on a central server, accessed from "dumb terminals" with  very little computational power of their own. A handful of firms already market the technology for desktop computer networks and are working on versions for handheld devices, which they hope wireless service providers will adopt within a year. The results could include anything from writing a grocery list on a cell phone to editing an Excel spreadsheet on a Palm Pilot-and sending it off as an e-mail attachment.

The technique can work in a couple different ways. Citrix Systems of Fort Lauderdale, FL, for instance, saddles network servers with all of an application's computational work, so that, according to senior product manager Steve Piper, "only the screen image is compressed and sent down to the client device," and "only clicks and keystrokes are sent back up." But even though compressed screen images and keystrokes require very little bandwidth individually, under the Citrix system they still shuttle back and forth almost constantly; it will take a pretty powerful bank of servers to keep up.

The competing approach is to break applications down into component parts and send users only the components they need at a given time. Of course, it isn't easy to figure out which components those are. Palo Alto, CA-based AppStream attempts to predict users' needs on the basis of past decisions; while Nortel Networks Application Management Solutions of Chelmsford, MA, hopes that, by breaking applications into small enough chunks, they'll be able to "see what the running application asks for and provide it on demand," says vice president of marketing Jon Friedman.