Good subjects and camera work are essential when it comes to producing good photographs.
As important however is timing.
Regardless of how skilful a photographer is or how gorgeous a model may be, images will never turn out good if a picture is not snapped at the right moment.
Acid Cow has compiled a series of photos showing images that were captured at exactly the right time, right down to the millisecond.
Have a look at them in the gallery above.