IBM is rolling out a new product that is meant to replace the traditional PC running a local operating system and applications.

The idea is to help businesses save the expense and hassle of managing a bunch of PCs. Eventually, it might help them break the PC upgrade cycle as well -- and cause lasting damage to PC makers like HP and Dell

The technology is called desktop virtualization, and it takes entire PC desktop and turns it into an image stored on a server. When users log on from work, they appear to on to their local PC, but in fact they're using an image of that desktop on a server.

When done properly, this helps people work from more locations and more types of devices -- they could use a Mac, Linux box, or even an iPad to access work -- and all their changes will be saved no matter where they're coming in from.

It also helps IT departments save a ton of money on PC management. Instead of having to install apps, patch, and help users with hundreds of different PCs, IT departments can simply maintain a few shared images on a server.

Companies like VMWare and Citrix have been doing desktop virtualization for several years, and Microsoft itself has products like Terminal Services that do the same thing. (Really, the idea of centralized computing goes back to the mainframe days, when IBM ruled the world.)

But these products can be painful to use -- there's usually noticeable lag between action (like typing) and response on the screen (words appearing), and they tend to fail completely if the network goes down.

IBM claims its Virtual Desktop, which uses technology from Virtual Bridges, will offer much better performance with less lag. The IBM Virtual Desktop also offers full functionality when users go offline -- on a cross-country plane flight, for instance, users can still access their work desktop, and when they reconnect to the Internet on landing, the changes are automatically synced up.

In the short run, businesses will save money on managing PCs.

But it can also lower hardware costs -- they'll be able to keep their current PCs for much longer, and when those PCs wear out, they could replace them with cheap terminals. Microsoft won't necessarily be hurt by such a transition -- the company collects a Windows license no matter whether customers are using Windows on real PC or a virtual one -- but PC makers like HP and Dell might be.

The solution will be sold exclusively through IBM partners and will cost $150 per user per year, not including whatever additional hardware or software licenses companies need.