While the "most ambitious application of flash will be to replace the hard disk," says Tso-Ping Ma, professor of electrical engineering at Yale University, hard-disk technology is a "moving target," with advances that will continue to allow its capacity to increase and costs to fall. However, he adds, because flash is lightweight and uses less power, it is "very attractive for certain high-end applications," such as portable video players and more expensive laptops.

In the near future, tablet PCs will likely be the first computers to completely adopt flash, suggests Norm Frentz, OEM marketing manager for industrial products at SanDisk. These portable computers might only need 10 to 20 gigabytes of storage, as opposed to the average laptop today with its 40- or 60-gigabyte hard disk. But by the end of the decade, he says, flash costs could be low enough that the price of large amounts of flash memory might not be as much of a barrier.

When it comes to completely replacing hard disks, however, the equation involves more than simply comparing storage prices, says Coughlin, it involves assessing in which applications flash makes the most sense. People might be willing to pay for a flash-based laptop, he says, if they see the benefits of one as significantly greater than a less expensive alternative. Frentz of SanDisk adds another plus: "Imagine a flight to Europe where you don't have to charge your laptop."