I did illustrations for an interactive on-line website from Discovery Channel. They used animation and illustrations to teach about such things as the animal life that eventually formed fossils:

There were about 52 of these illustrations. They were done in Photoshop from scanned drawings.

We also did illustrations in 3D to teach about energy efficiency in different climates, using different technologies for heating or insulation. The below illustrations were created in Maya and Photoshop. They were coordinated in layers, so that they could be interactive, and low bandwidth as well.

There were four different houses done like this, in three seasons, with three types of insulation, in three geographic locations, and with 5 different types of heating elements, so you can imagine the coordinated layering..

Click through the thumbnails for an idea of the action: