Modular computing may be next wave.(Knight Ridder Newspapers)

Personal computer design has hit a wall.

By and large, we have rectangular desktop PCs and flip-up laptop PCs. There's the occasional deviant, such as the adjustable iMac, but even that works about the same as the others. In these days of sameness, consumers are increasingly waiting on the sidelines unconvinced that they should plunk down a few hundred bucks for a new machine when the old one works fine.

So where is the idea for a new, new thing? Consider a device that was announced at the Microsoft conference in Seattle last month. It works kind of like a Nintendo cartridge or an 8-track tape. It's about the size of a pack of 3-by-5-inch index cards.

Excited tech evangelists speculate that at last, we have a full-fledged Windows PC that actually fits in your pocket. It's called a modular computer. It works like a Palm handheld with a touch screen. Better yet, it can slip into a laptop or desktop computer's body, allowing you to take it where you want, and use it how you want. ...