In our HTML II class, we discuss the use of CSS-based animation. One of the more abstract concepts we discuss is the Easing timing functions. Trying to describe these in words alone is only so effective.
Ceaser is a nifty tool to help view the different ways that we can control our transition animations. It uses an intuitive image-based interface where you can see the effect of changing different parameters. And as an added bonus, once you have that transition just right, you can copy the generated code snippet and paste this straight into your own CSS stylesheet.