The following image was created using 10 photographs:
In example 1 below, the focus was on the foreground. The focus was then adjusted slightly for the remaining 9 shots, with the background being sharpest in the last shot – see example 2.
The 10 photos were then merged in Photoshop CS5 and using Auto-blend layers, a stack was created combining the sharpest points from every shot.
Quite affective and very easy to achieve but a tripod is a necessity.