There’s still plenty of hype, but nanotechnology is finally moving from the lab to the marketplace.

Hew nano-based products that could have a big impact are only a step or two away.

Within the next two years, diagnostic machines with components built at the nano scale should allow doctors and nurses to carry pint-size laboratories in their briefcases, perhaps to test for HIV or count white blood cells on the spot. Nano sensors will scour airports and post offices for anthrax and sarin. Toward the end of the decade, scientists say, new computer memories composed of nanoparticles could conceivably pack the digital contents of the Library of Congress into a machine the size of a yo-yo.