World finals for the 30th annual AMC-ICPC were held in San Antonio, Texas. Competitors were given 10 complex problems to solve within an allotted time by using computer programming.

The 10 problems challenged programmers to create software for everything from data decompression to origami. One problem asked programmers to design a structurally sound sculpture, restricted by the physics of a specific set of materials and specifications. Another challenged them to write a program that could instruct on how to assemble a clock with minute and hour hands, given a specific shaft speed and collection of gears.

Winners were determined first by the number of problems solved within the allotted time, then by the time it took them to do it. The Saratov State University team completed six of the 10 problems in a little over 15 hours.

Each of the Saratov State University team members won $10,000 in scholarship, computer equipment from IBM, an event sponsor and the prestigious world title to put on their resume.

Other than six total slots taken by Russia and the U.S., three other countries made it to the top 10. Poland's Jagiellonian University placed second, and Warsaw University took seventh. A team from the Netherlands took fourth place and one from China took fifth.

Another American university, California Institute of Technology, shared 15th place with 39 other schools, solving only two problems. Other U.S. universities that participated have received honorable mentions for making it to the finals.

Tim Brown, the district's director of operations, confirmed some students used buckets but said the principal's order to impose the most severe type of lockdown was an "honest mistake."

"When there's a nuclear attack, that's when buckets are used," Brown told the Los Angeles Times. The principal "followed procedure. She made a decision to follow the handbook. She just misread it."

A message left by The Associated Press for the principal at the school before business hours Monday was not immediately returned, and Marquez did not return telephone calls from the Times.

Appalled parents have complained to the school board. Brown said the school district planned to update its emergency preparedness instructions to give more explicit directions.

Parents and community activists asked the school board at its April 5 meeting to explain the principal's decision. They also sought promises that the lockdown wouldn't be repeated.

"There was no violence at the protests, so this was based on what?" activist Diane Sambrano asked. "It was unsanitary, unnecessary and absolutely unacceptable."

From gadgets that will sweep and mop floors to robots that will look after people, hi-tech products may well help buyers circumvent the headache of trying to find affordable and reliable domestic help that do not require government papers or tax filings, not to mention sick days and time off.

"We provide peace of mind," said Martin Spencer, chief executive of Atlanta-based GeckoSystems, which specializes in making domestic-use robots, most notably its Carebots. On sale for the past six years, Carebots have a built-in video camera with videoconferencing capabilities, in addition to having all the functions of a personal computer.

"You can train it and customize it to look out for the kids and grandma," Spencer told United Press International. For instance, the four-foot machine can be programmed to follow a child around the house while the mother is at the office, and she will be able to see through the robot's eyes what exactly her offspring is up to.

And if he's touching something he isn't suppose to, not only can the robot be taught to say "no," but the mother can boom her own voice out through the robot from her office desk.

It can be trained too to tell the child to do homework, pick up after itself, eat dinner, and all the other things a parent might do at appropriate times -- and it can even learn to sing and tell jokes too.

The single biggest potential for home robots, though, is in elderly care, Spencer argued.

"This can keep grandma out of the nursing home," he said, pointing out that half of the nursing homes in Florida are juggling with lawsuits as they provide sub-par care, even as it costs several thousand dollars to keep them there.

The problem with robots, though, is that they too aren't cheap. The price tag of a Carebot is $20,000, even though it does include a couple of days' training for the new owners so that they can make full use of their purchase. It is also probably not an easy tool to use for those who feel uncomfortable around computers and tech gadgets or otherwise don't see themselves in the category of technically advanced families.

That's certainly not the case when it comes to the mopping and sweeping machine.

The Scooba by iRobot is definitely affordable, even though it's far from cheap. The mopping machine costs $400, and its sister, Roomba, which vacuums the house, ranges from $150 to $300. Moreover, it's simple to use for even the most technologically disinclined.

All Scooba needs is a capful of special cleaning solution specifically designed for use in the robot mixed with warm water put into its tank, and with the press of one button, it can be left on its own to prep, wash, scrub and dry a tile, linoleum or sealed hardwood floor.

"It does what it's supposed to do very well," said Nancy Dussault, director of global marketing at iRobot.

That it certainly does, but the problem is, it doesn't do anything more than that. So while the kitchen and bathroom floor may be spick and span, it's still up to humans to wipe down counters, do the dishes and throw out the rubbish. So while a machine might come in handy between days that the cleaning lady doesn't show up, it will never act as her replacement.

And therein lies the problem with affordable robotic technology for households as it exists today. While knowledge from advance military defense capabilities may be used in developing the products, robots for the home are only able to accomplish basic, repetitive tasks. For those simple tasks, they are very good. But a seemingly menial task such as cleaning a house actually requires considerable dexterity and skill that is beyond a basic robot's ability. Meanwhile, if a machine is even slight programmable, the cost for the product becomes prohibitive to most people.

"There really aren't that many products available in the market that work at home at a low cost right now," said Jeff Burnstein, vice president of marketing and public relations at the Robotic Industries Association based in Ann Arbor, Mich. "So when it comes to talking about the impact (of robots) on immigration ... it just isn't there yet," he added.