You may have heard of the story of the man who crossed the Canadian border using only a photo of his passport on his iPad as his identification.
http://technabob.com/blog/2012/01/04/ipad-passport/
Granted, when traveling, you should always have backup photos of your identification, your credit cards, etc. stored somewhere safe, maybe stored online so that you can access it in case your wallet was stolen. But, don’t try this yourself kids! Just because you may have read it on the internet doesn’t mean it’s always true.
The Candian Customs says that this never happened. (http://www.wired.com/gadgetlab/2012/01/ipad-passport-customs/) And with further thought, this should NOT ever happen, given the many magical things that can be done these days with Photoshop.