One of the very popular demonstrations used in introductory physics courses to illustrate Lenz's law is the "slowly falling magnet." In its simplest version it requires only a powerful cylindrical magnet and a metal tube, typically of copper or aluminum. When dropped in the tube the magnet takes significantly longer to reach the other end than a geometrically similar but nonmagnetic object. This demonstration has been adapted for use in large classes using a camera to monitor the magnet as it approaches the end of the tube. Small versions that can be used for hands-on experiments also have been developed or are available commercially. This classical demonstration in its various forms almost never fails to impress first-time viewers. (Contains 4 figures.)