[Forseti]

Any good to you?

http://en.wikipedia.org/wiki/Focus_stacking

http://www.wonderfulphotos.com/artic...ocus_stacking/

http://prometheus.med.utah.edu/~bwjo...658/index.html

and for views on some of the different software available http://www.laurieknight.net/article/view/7

Typing in 'focus stacking' in Google throws up page after page of information.