I manipulated some images replacing the thumbnail present in the photo exif header. I would be interested in transferring such a photo to an iPhone anyway everytime I transfer it via e-email or in some other way exif informations are wiped out.
I would be also interested into know if it is possible to replace such informations, like thumbnail header exif, directly in an iphone app through iOS Sdk and then save the modified photo in the photo roll without loosing the exif header.