You might have seen the video from earlier this month in which a basketball was dropped several hundred feet from the top of a dam. The backspin on the ball caused it to do something very cool.
Well, the folks behind that video decided to step it up a notch and did the same experiment from a several hundred meter tall cliff. The effect is still, well, in effect and makes for a pretty interesting video.
A brief primer on the Magnus effect, from Wikipedia:
The Magnus effect is the commonly observed effect in which a spinning ball (or cylinder) curves away from its principal flight path. It is important in many ball sports. It affects spinning missiles, and has some engineering uses, for instance in the design of rotor ships and Flettner aeroplanes.
In terms of ball games, topspin is defined as spin about a horizontal axis perpendicular to the direction of travel, where the top surface of the ball is moving forward with the spin. Under the Magnus effect, topspin produces a downward swerve of a moving ball, greater than would be produced by gravity alone, and backspin has the opposite effect. Likewise side-spin causes swerve to either side as seen during some baseball pitches, e.g. leg break.
Here is the original video and some more info on the Magnus Effect.