This hands-on activity demonstrates and explains the reasons for the seasons caused by the tilt of Earth on its axis as it orbits around the sun.

An interactive simulation of Earth's seasonal dynamics that includes the axial tilt and other aspects of Earth's annual cycle.

This is part of a larger lab from the University of Nebraska at Lincoln:

An applet about the Milankovitch cycle that relates temperature over the last 400,000 years to changes in the eccentricity, precession, and orbital tilt of Earth's orbit.