Eideitic memory or, more colloquially photographic memory is the ability to vividly and faithfully recall information after minimal exposure to it, without using any sort of mnemonic device. It usually relates to visual images, but in some cases encompasses auditory information as well.
The phenomena is rarely seen in children (in about 2-10% of children aged 6-12), and is unknown in adults.Where it does appear in adults, it is often tied to a single group of information and is often associated with savants.
See also Hyperthymesia or superior autobiographical memory, a fairly well documented phenomenon.