If you're looking for a better earthquake warning system, or a better way to track lost children, computer science students from around the world have the solutions.

A group of students from Tribhuvan University in Nepal stood before a group of judges Monday and told them why their GPS-powered (Global Positioning System) earthquake warning system -- including US$20 (AU$28.95) receivers that people can carry with them -- would be popular around the globe. The inexpensive system, which would send users warnings of earth rumblings via radio towers and US$200 (AU$289.50) earthquake sensors, could appeal to a large number of people living in earthquake zones, said Aashish Dutta Koirala, a member of the Nepal student team.

"An earthquake doesn't discriminate," Koirala said to judges at the world finals of the fifth annual Computer Society International Design Competition held in Washington last month.

The Nepal team was one of 10 finalists, hailing from universities from Rio de Janeiro to Taipei. The finalists, narrowed from 250 entries in the competition, demonstrated and explained their work before a panel of judges during the four-day event, with this year's theme, "making the world a safer place."

The Tribhuvan project, called TremorFlash, would allow users to signal back to the transmitting location that they were safe after an earthquake. Users who don't send back a "safe" message after an earthquake can be treated as in danger, and the local government can send out emergency teams, Koirala said.

The Nepal presentation included a Flash animated cartoon where a user, sitting on a couch, screamed "Ahhh!" when his receiving device notified him of the early underground rumblings of an earthquake. The cartoon characters then crawled under their bed before the earthquake hit and were safe from damage.

The Nepal team and a team from the Politehnica University of Bucharest both used tools from competition sponsor Microsoft in their projects. One judge joked during the Romanian presentation that it shouldn't be a commercial, but the students plowed ahead with their description of eXpress! Help, a peer-to-peer emergency assistance software package added to cellular phones.

The Romanian team uses GPS on mobile phones to pinpoint a lost child or elderly person -- allowing family members or authorities to find them. Their project also uses the Bluetooth short-range wireless standard to signal other eXpress! Help users in the vicinity of the person needing help, using community volunteers to offer assistance to those in need.

"Our target is to enhance the 911 emergency services by finding people inside the community and letting them help each other," said Andrei Hagiescu Miriste.

The Romanian team showed a short video where a student was lost on a field trip, but was found quickly by his teacher through GPS tracking on the teacher's cell phone. Other eXpress! Help users in the student's area saw a picture of the lost student on their cell phone screens.

When one judge asked why people would be willing to help others, student Marian Mihailescu said users of the software will treat others the same way they would want to be treated if they were lost or in need of other help.

While the theme of the competition was on making a safer world, most projects centered on projects other than the current U.S. focus on fighting terrorism. A project from the University of Virginia strung together a series of water-quality sensors to test rivers for pollution and pinpoint where the pollution was coming from. The project was called "The Polluter Must Pay."

An Iowa State University project, called Spatial Cue, allows users to put reminders on their PDAs, based on physical locations. When a user passes a video store where a rental is past due, the PDA will alert the user to return the video. The system can also be used to relay the location of rescue workers back to a central dispatch, team members said.

The winning team in the competition wins US$15,000 (AU$21,709), with second place taking home US$10,000 (AU$14,472), and third US$6,000 (AU$8,684). There are also awards for multimedia and software engineering.

The Nepalese team, which had its presentation on Monday delayed a couple of minutes because of hardware problems, said they came away from the contest with more than software development skills. "More than anything, this contest has educated us on disaster management," Koirala told the judges.