Engineering! Fun and applicable! (Score 4, Insightful)

I've always thought that teaching something that combined science, engineering, and Vo-Tek would be highly practical in high school.

How about Small Engines? You can buy a small lawnmower engine (and a manual) and teach them principles of mechanics and combustion while also levening parts of "how things work" as well as basic repair techniques. Eventually you put the thing back together and start it up. You can even show how to mess with it to trick it out or solve common problems.

Not only would this get kids interested in science and engineering, but it would be practical.