Washington—At the finals for Microsoft’s U.S. Imagine Cup competition, which took place here today, 20 student teams displayed video-game and software projects that attempt to solve the world’s greatest problems with technology. James Cameron, the Academy Award winner who most recently directed Avatar, spoke at the awards ceremony.

Some projects had a very practical use, such as software that would make medical data more available to researchers around the world. Other projects, however, were designed more for entertainment, such as a video game that lets players fight disease in the human body using tiny robots. Of the teams, which were mostly made up of college students, two were selected to represent the United States in Warsaw at the Worldwide Finals in July.

In the software-design category, three students from the University of California at Davis took the prize. The students’ project, called “Mobilife,” is a tool that uses Windows Mobile platform and computer-assisted intravital microscopy to help diagnose vascular diseases in children of developing countries.

In the game-design category, a team from Central Piedmont Community College and the University of North Carolina won with a game that involves a series of quest challenges. The main character is a child in a developing country who must go through obstacles to meet a need, such as finding clean water. The name of the game, “Sixth,” refers to the one-sixth of the population in developing countries that live in slums.

Mr. Cameron talked about his personal connection to the message of the Imagine Cup competition, and lauded the students for using technology for the greater good.

“It’s technology that got us into this mess,” he said, referring to climate change. “And it’s technology that’s going to get us out.”

But Mr. Cameron also mentioned that he could use some of the talent that was there out in Hollywood.

“I’m hoping to be able to work with a number of [these students] in the next few years,” Mr. Cameron said.