There is a great TEC module that comes with the Stewart Calculus text CD that has students examine the first and second derivative curves and determine properties of the original function by placing this information on sign charts. I just used this module in a video lesson for my online Calc class, and it can be found on the Internet here, so I thought I would share it with you. It could certainly also be used in a traditional class if you have a computer and a projector.
There are four different examples you can use. I walked students through the first function in a video, and then assigned two other functions for participation points (they can take screenshots and submit them).