Virtual Machines for Small Form Factors?

Tim O'Reilly writes about the value of small form factor devices connected to Internet data...

It's a sign that special purpose hardware providing access to internet data services may eventually be commonplace.

On the other hand I don't want to carry around five or ten devices. I'd rather have a three form factors and carry around one of them, the one that is most useful for the moment. That may be a wrist watch sized device, a larger cell phone sized device, or a small laptop sized device.

I'd like virtual machines running on each of these with images of the systems I want to use. Most of my systems would run on any of the form factors and use as much of the capabilities of each as possible. Everything would be synched, backed up, and enhanced through the Internet to my big system that stays put at home and/or at some other site.

People with ideas for new capabilities would not design new hardware, just new virtual images for the common hardware. Every year or so I would upgrade one or more of the devices to the newest physical devices available. All the old images would continue to run.