Another challenge is that the memory experts we've worked are not that interested in photographic memory. Even Paul Scheele--he'd rather spend his r&d time on other topics.
I've spoken with several (if not more) folks who have photographic memory, and they have said they can recite from their memory, but they don't understand the material unless they read it in their mind's eye.
Well, that's easily solved by PhotoReading and activating the information to build understanding. The photographic memory would be there for the at-will details.
I wonder how long that eidetic image is easily recalled. As it is, I am amazed at how much information goes into my head and how much I remember now. And, when I don't remember something, I don't fret much, because of the vast quantities I do remember.