Imagine cramming 30,000 full-length movies into a gadget the size of an iPod.

Scientists at IBM said on Thursday they had moved closer to such a feat by learning how to steer single atoms in a way that could create building blocks for ultra-tiny storage devices.

Understanding and manipulating the behavior of atoms is critical to harnessing the power of nanotechnology, which deals with particles tens of thousands of times smaller than the width of a human hair.

One of the most basic properties that every atom has is that it behaves like a little magnet, said Cyrus Hirjibehedin, a scientist at International Business Machines Corp.'s Almaden Research Center in San Jose, California.

If you can keep that magnetic orientation stable over time, then you can use that to store information. That is how your hard drive works, Hirjibehedin said in a telephone interview.

What we are trying to understand is how this fundamental property works for a single atom.

Hirjibehedin and colleague Andreas Heinrich studied this property -- known as magnetic anisotropy -- in individual iron atoms using a special microscope developed at IBM.

What we've been able to do is to look at an iron atom on a copper surface and to move that magnetic orientation around, Heinrich said.

Now they are looking for an atom that remains stable over a long time. We have a couple of ideas but we don't really know which ones will work out, Hirjibehedin said.

In the very long run, we're shooting for data storage on a very tiny scale, he said.

IBM colleagues in Zurich, Switzerland, meanwhile, have stumbled on a way to manipulate molecules to switch on and off, a basic function needed in computer logic.

They had been evaluating the vibration of a molecule when they noticed it had distinct switching capabilities.

Heinrich, who is familiar with the work, said the discovery is especially important because the switching action did not alter the framework of the molecule.

Switches inside computer chips work like a light switch, turning on and off the flow of electrons that ultimately make up the electrical circuits of computer processors.

Molecular switches could be used to store information and would lead to super-fast, super-tiny computer chips.

The two discoveries, which were published in the journal Science, will one day form the basis of future devices the IBM scientists were reluctant to even speculate about.

Put yourself in the situation of people in the '70s, where they had a roomful of computing equipment that could basically do what you can do nowadays on your cell phone, Heinrich said.

They would have given you some really stupid answers.

Ipod California Ibm