Does anyone remember the trial balloon title for the movie E.T.? It was "The Extraterrestrial at Home." They shortened it to E.T. during filming.

I mention this because I have had E.T. on my mind the past six months. Like many of you, I downloaded the SETI@home screensaver from the University of California-Berkeley.

For those of you who have living on another planet, SETI@home is an experiment in coop bioastronomy. The name stands for "Search for Extra Terrestrial Intelligence (at home). The project, whose derives from an interesting computing problem.

You may know that radio telescopes have been scanning the heavens for years listening for any kind of deliberate-sounding radio transmission -- anything other than the white noise we generally receive from space.

And you doubtless thought, well, astronomers have computers. They can sift through all that radio data themselves.

But it's not true. Space turns out to be very, very -- spacious. Every day, a radio telescope in Arecibo, Puerto Rico -- the world's largest -- receives 35 gigabytes of radio data. This data is recorded to magnetic tape, and is shipped via snail to Berkeley.

The problem is that that much data is too much even for the biggest massively parallel-processing supercomputer at the biggest university.

So someone at SETI had a thought. A Mickey-Rooney, there's-a-stage-in-my-dad's-barn sort of thought. What if, instead of using a single supercomputer, the work were portioned out to a couple million volunteers?

A clever programmer created a way to divide the data into 250 kilobyte packets, downloadable by volunteers. Then, while you sleep, or grab a donut, SETI@home combs through your own personal forty acres of distant space.

What is it listening for? Any sharp variation to the white noise that fills the 35 gigabytes of data received daily -- a spike, an irregular pattern, a yip, a yawp.

I signed on as an E.T. hunter in August, and in the intervening weeks have combed through only three of these packets, and loaded them back to SETI. It is a slow, meticulous process, and you must be careful to set your SETI@home to screensaver, not multitasking mode. Or your computer will slow way down.

It's been interesting. Sometimes, coming across the computer in screensaver mode, I have just sat watched the device mill through the noise.

The program creates a compelling computer pattern as it churns the bleeps and fizzles. The pattern puts me in mind of a thousand pink and blue punchcards being lifted by an invisible hand from a cosmic catalog. Each card is examined for any sort of distinctive sound, then it is slid back into place.

Every now and then a card rises a bit higher than the cards before it, and you wonder what it was. A pulsar? A cry? A siren on another star?

But if my PC came across any reruns of My Favorite Martian being broadcast from some crab nebula out there, I'm unaware of it.

But it is something to think about. You could discover E.T., like Eliott. Or you could detect less personable lifeforms, plasma people perhaps. Whether you prefer one or the other is a kind of quickie personality test.

But I'll tell you what gets me about this story. Not E.T. Not plasma people. Not even that big radio antenna in Arecibo -- where the fight scene in the James Bond Goldeneye movie was shot.

What gets me is the idea of megadistributive computing. At present some 1.3 million people have signed on to provide computer time to SETI. That's more people than participated in Hands Across America on May 25, 1986, the human chain that crossed a continent, give or take a few hot miles around Barstow.

If people can pool their thinking resources to find E.T., perhaps algorithms can be devised that work on solutions to even knottier problems. Solving the problems of poverty, hunger, and disease. Creating ways ordinary people can stand up to the brute forces that are massed to, in the words of poet James Wright, sell us our deaths. Finding the fulcrum between dreams and reality.

Perhaps it is unrealistic to suppose that such problems could be encapsulated by a data string. But complexity science suggests that our experiences stack up remarkably well next to the experience of the cosmos as a whole.

What did I read once -- that the size ratio of an electron to a complete human is roughly similar to estimated size ratio of our sun to the universe. Googol everything.

Human experience is like those fractal drawings, in which the immense follows the same pattern as the minuscule, the way an intricate seashore seen from space resembles the contour of a single grain of sand.

What if we all worked on cracking the puzzle together?