The Centre for Innovation in Engineering and Science Education has a great list of collaborative science projects for all ages. Topics include Human Genetics, the Global Sun Temperature Project, Water (“The International Boiling Point Project”, “Bucket Buddies” and “Take a Dip”) and measuring the circumference of the earth. CIESE sponsors and designs interdisciplinary projects that teachers throughout the world can use to enhance their curriculum through compelling use of the Internet. They focus on projects that utilize real time data available from the Internet, and collaborative projects that utilize the Internet’s potential to reach peers and experts around the world.
They also have a great list of “Ask an Expert” sites, where you can go to ask real scienctists questions about their work. The internet has really broadened student horizons and given them opportunities to discover life, work and play outside the classroom!