The Global Challenge is an interesting competition for high school students. From the website:
In the Global Challenge, teams of US high school students collaborate with international counterparts from October to May to address global climate change and compete for prizes and scholarship awards!
International teams of four high school students (2 U.S. and 2 from another country) work together over the Internet to identify a solution that addresses some aspect of climate change and the future of energy.
This is a program that has been running for a number of years that works to get students to apply what they know (and encourage them to learn more) and science and technology by applying it to global problems. Besides the focus on Science, Technology, Engineering and Math I love the international aspect of this. Creating and working with teams in different countries is a "real life" experience that can't help but contribute to future career success. And of course to international understanding. A lot of great goals wrapped up into a fun and interesting change to win prizes.