This is an actual photograph, not a digital creation or composite image. For these interested in technique the trick here is a long exposure of 1/2 second with flash synchronised to second curtain. This means the whole view is exposed for the whole 1/2 second but the flash only fires as the exposure is being completed giving a ghostly appearance to the kid on the swing. The aperture controls how well exposed the elements will be and how much movement in lapsed time will be captured.
Photo created using Canon 30D, Tokina 12-24 F/4 lens and Canon 580EX Speedlite in E-TTL II mode.