Thinking Outside the Box-Shaped Photo: How to Create Cool Photo Edges in Photoshop CS2
http://www.informit.com/articles/printerfriendly.asp?p=444219&rl=1

Cross, Dave
InformIT
2006

Abstract:

Don't be satisfied with boring rectangular photos! Thanks to Photoshop, you can use simple techniques to create amazing edge effects and cool artistic borders that can add the ultimate finishing touch to your photos. Dave Cross shows you how easy it is to create many different variations from three key techniques.