What's interesting to me is that Microsoft has finally acknowledged that there is a class of machines that people are interested in manufacturing that are ultra-low-cost, and yet use flash as a storage medium. Solid-state disks are several times more expensive than a conventional magnetic disk drive (for example, this $2,000 64-Gbyte laptop drive)

but as any camera buff knows, low-end flash card prices seem to be perpetually heading downhill.

There's a caveat here, of course: even a gigabyte of flash costing $20 or so still is a significant percentage of a $399 machine (or, more precisely, pair of machines). And, of course, there's the added value in the ruggedness solid-state memory entails.

For Microsoft, there's also a technical consideration, as explained on the Unlimited Potential blog:

"As part of this engineering effort, we have to design a new BIOS - the layer of software that runs between the hardware and an operating system -- to have Windows boot and run off the SD card. For us this is new work and requires a design and processes for supporting the XO's custom SD interface and for the installation of Windows on the SD card, both at the Quanta factory that manufactures the XO hardware and also in the field."

Fujitsu's Tablet PCs already include flash memory as a standard feature. Wonder how many low-cost PCs, as well as tablets, flash will intersect in the future?