http://iphonedevsdk.com/forum/iphone-sdk-development/101180-how-to-enlarge-picture-in-uiimageview.html

http://stackoverflow.com/questions/11393696/show-an-image-as-enlarged-on-clicking-an-image-view-in-iphone

http://stackoverflow.com/questions/13798949/enlarge-image-view-on-ios

http://agilewarrior.wordpress.com/2012/01/25/how-to-display-image-on-iphone-using-uiimageview-and-uiscrollview/