Yes, cleaning! Enough with the Higgs, and the Dark Energy, and the pnictide superconductivity. Let's get dirty and learn about the physics and chemistry of cleaning!
This brief overview actually came from a janitorial service company, but it has a nice article on the chemistry of cleaning, with lots of external links if people care to read more. It's one of those things that we use and encounter each day, but for many of us, we don't give a second thought on how or why it works. So wash your hands (with soap), sit down, and learn what you just did.