His software, 3^RDPlanit, is a specialized CAD program for laying out model railroads. Most people who decide to get into model railroads want to build a model railroad immediately, but they don't have the first idea how to do it. They need almost five years' experience to build one. Instead, the computer offers a faster and practical solution to designing an indoor railroad.

3^RDPlanit will start with the smallest size circle that will allow the cars to make it around the curves. The program is aware that track needs railroad ties and rocks, or ballast, underneath and provides those features. It is also 3D, so it allows you to see how your plan works out. For example, it will add easements-sections of track that ease into a curve-and will show you how they take the train into a turn when you take a virtual train ride. 3^RDPlanit has simulation capabilities as well. As you're taking your train ride, you can look out the side windows on your way down the track and determine where to place vegetation, for example. 3^RDPlanit even supplies individual trees and shrubs and allows you to select objects to animate, such as a crane that goes up and down.

Another feature of 3^RDPlanit is auto-alignment. If you draw a piece of straight track somewhere and then you move it over to another piece of railroad track, it knows to auto-align the piece. Likewise, if you draw an S-curve, the program automatically inserts an easement to allow the train to gradually decelerate as it comes out of one curve and accelerate as it enters another, which prevents the cars from derailing on curves that are too tight.

In developing this software, Pfeiffer has taken into account the practices of the American Railroad Engineering Association and some of the European associations, as well as model railroad practices. For those with limited space, this virtual railroading allows you to do the same elements of track planning and problem solving that you would do on a model railroad. For those who have various hobbies, such as astronomy, it has additional features, such as allowing you to animate the solar system. For example, you can see the planets going around the sun, and the moon going around the planets, or set up the Earth going around the sun, and you can see how the seasons change.

If you visit the Web site, you can download a demo version as well as see some great pictures taken from a train in Germany (where Pfeiffer got to "drive" a train a little way). The program costs $100, but a $20 discount was given to those who purchased it at the meeting.

SETI stands for the Search for Extraterrestrial Intelligence. Basically, SETI searches for signals in space that correspond to our own emissions, such as radar and TV. The only way we know how to do that right now is to listen to radio waves coming from stars and to find the ones with properties that don't occur naturally.

Radio telescopes have been searching for waves for about 40 years. A man in West Virginia by the name of Frank Drake had the idea in 1960. He used an 85-foot dish and ran the waves through a spectrum analyzer. He didn't find anything, but others have since undertaken similar projects. At the same time, the technology used in telescopes and computers has evolved, yet the computers used to analyze the frequencies are not really fast enough to analyze the signals as well as we would like. They very likely miss faint signals buried in noise and, because stars are so far apart, if we got anything, it would probably be just a very, very faint signal.

The SETI@home project is the brainchild of Dave Gedye, who wanted to find a way to get around these obstacles to analyze the large amounts of data SETI gathers from its telescope. His plan was to harness the computing power of individuals' PCs by tying them together through the Internet into a parallel supercomputer. To do this, SETI@home gives participants a program, which runs as a screen saver while it evaluates the data sent to your computer during its downtime. (SETI will soon come out with a new version.) The program uses only about 16 MB of RAM.

SETI is presently examining a small band in the sky with about 10 times the sensitivity that any other project has been able to do-until now. The project acquires its signals from an antenna on Arecibo in Puerto Rico and then records them on a digital tape recorder using tapes that hold about 35 gigabytes each. The data on the tapes are broken up into two-minute "jobs," or segments (about a third of a megabyte), which are then downloaded onto participants' personal computers. Each job takes about 20 hours to evaluate. When the evaluation is complete, the data are then returned to SETI@home and entered into a database.

The project's basic task is to look for "candidate signals" that may be a sign of life. The fundamental pattern of one of these signals is a bell-shaped curve along a narrow ridge. So far, all of the candidate signals have been manmade interference.

A second phase of the analysis takes place only after SETI has collected the results of many of these jobs. During this second phase, SETI determines what is interference and searches for repeat signals that occur at the same frequency and at same point in the sky several months apart. If that happens, it is highly probable that they are actually signals coming from space and not manmade interference. The project will run for two years, hitting every point in the sky three or four times, so it will be able to do this repeat detection.

When SETI@home first went public with its parallel computing plan, it had no idea of the response it would get. It had quite a bit of help getting the project off the ground, however, when Paramount Pictures came in early 1998 with a $50,000 donation. A clever PR guy convinced the studio it could use the project to promote the latest Star Trek movie. The project now has about 1.5 million PCs in 224 countries participating in the project and has accumulated well over 100,000 years in PC computing time in just six months. The project is averaging about six teraflops/second (six trillion operations per second), making it six times more powerful than the most advanced supercomputer available today and rendering the SETI@home project the largest computation anyone has carried out.

Because it has had such a good response, the project would like to add more analyses, such as searching for sign waves. At the end of two years, SETI@home may consider examining other frequency bands from Arecibo or other radio telescopes. It could also apply the same technology of distributive computing to work on other scientific projects: genetics, biotechnology or ecological simulations, for example. It would be great if it could produce a screen saver that has a menu of choices to use your computer time: find alien life, cure cancer, prevent global warning or whatever you decide is important to use your CPU power for.

SETI receives donations from the Planetary Society in Southern California, who put it in touch with Paramount, as well as Fuji, Sun, Quantum and Intel, which is supporting it a little. Donations of equipment and computing time are important because the federal government cut SETI's funding in 1992. Nevertheless, SETI@home has been extremely successful in involving a great many people in a real science project. It has also taught people about SETI, emphasizing its research value-reversing the opinion that it's just a hunt for flying saucers or UFOs.

SETI's Web site provides more complete information on the project, including the amount of computer time used broken down by computer types, a breakdown of work by countries, individuals, groups or organizations that are competing to provide the most computer time.

So, if you want to know if there is extraterrestrial intelligence, then give SETI@home a call. What better way could one use computer's idle time? Although the sounds wouldn't necessarily mean there is life out there now, as it takes time for sound to travel, who knows?