This is a step-by-step example of entering data, graphing it, and finding the (exponential) regression equation. It is easily adapted to any data that you would collect within your class.
Before the Activity
You might want to collect your own data to be used with this as a guide.
Before the activity, chose an experiment and collect your data.
During the Activity
The students should be able to work on this independently as the teacher circulates and keeps people on track.
I would ask a more capable student to connect their handheld to the overhead projector.