One of the ways that I have found to get kids interested in science is to relate it to something that they are interested in. For teenagers three of the most fascinating topics are sex, drugs and rock and roll. While you may have to be careful about approaching these topics, they can be used to inspire some very interesting science experiments.
The subject of sex can be integrated into a G or PG rated science project by examining human behavior. Science experiments can be set up to examine how boys flirt compared to how girls flirt, or how older adults flirt compared to how younger people flirt. Clothing choices and ornamentation can also be examined from various cultures to see what is considered attractive.
When using drugs as a topic for a science project it is important to monitor how the project is set up. Human testing is not generally allowed for kids in elementary or high school level science fairs, so you will want to examine the chemical components of drugs and use pre-existing data to link physical reactions to drug use. You may also want to set up scientific research projects that examine how cultural opinions about drugs influences the types of drugs used and how often the drugs are used. Safe drug experiments can look at the number one drug for teens, caffeine.
Rock and roll is probably the safest of the three topics to explore. Sound experiments, wave length experiments and the reaction that certain types of music has on heart rates can all be great ways to explore the world of rock and roll from a scientific perspective.
Teachers and parents need to find fun and exciting ways to get kids interested in science. Science experiments that utilize topics that kids are interested in are just one way to get them involved. When selecting topics for school science fair projects or state level science fair projects, try to utilize pop culture as a source of inspiration.