Ideas for Scientific Experiments to be Done in Space?

Mark Shuttleworth asks: "I'm hoping to launch an African Space Program by flying to space with the Russians. There have been some ups and downs along the road ;-) There is still no certainty, but the battle is half the fun. The program includes science, education and media. We have some great science experiments submitted by South African scientists, in physiology, genetics, proteomics and stem cell work. I wonder what ideas the Slashdot community has for world class space science or education, or other suggestions to make this project a huge success for Africa? If someone has a great idea, and it requires only safe, light, COTS equipment, I will try to get it onto the flight when/if I ever get up there. Any ideas are welcome. I'm looking for science experiments that are of interest to Africa, that are cutting edge, and that can only be done from space. Or educational things that demonstrate fun science that is uniquely possible in space. And yes, Debian, Python, Mozilla, POV, LAME, TTR and other friends will ride along too."