According to the commercial jingle, the slinky was "a wonderful toy, fun for a girl and a boy." The spring-shaped toy, which had its biggest run of popularity in the 60s and early 70s, was also good for a few tricks that made the coil appear to move on its own. Some of them can still be done right out of the box, while others may require a fair amount of practice.
Place a slinky at the top of a set of stairs, and pull the first few rings down to the next lowest step. The rest of the slinky will pull down to the next step, then flip over itself and move down to the next lowest step. It will continue down the steps to the bottom.
Hold the slinky in your hands in an upside-down U-shape, with one of the legs (and around half of the slinky) on each palm. Raise one hand, and the slinky will start stepping down toward your lower hand. Before the slinky runs down to the other hand, bring the upper hand below the first, and the slinky will slink down to that hand. Go back and forth for a simple building block to other tricks.
Lay the slinky on its side on a table. Tie or tape it to something, or have someone hold it in place. Stretch the slinky out to the other end of the table. Shake the slinky up and down to mimic a transverse wave. Push the slinky toward the other end of the table and pull back to make a transduction wave. You can also combine the two, and have both types of waves at the same time.
Begin with the hand-over-hand trick. When the slinky starts running out in your upper hand, gently toss the bottom of it and catch it in your upper hand. The top of the slinky will start pouring down on top of that. Catch the falling top in the lower hand. Repeat the step to start a juggling effect. The slinky will appear to go down your hands in one direction.