"The Art of Memory", collective name given to comprehensive mnemonic techniques developed in antiquity to aid in the ability to store and recall prodigious amounts of raw information before the conveniences of computers, notecards, or reference manuals. Supposed to have been used fairly extensively by the marathon orators of the ancient world, to hold together the dissertation-length addresses they would compose and deliver on topics of legal disputes, politics, history, culture, etc.

Revived briefly in study during the Italian Rennaissance, notably in the work of accused heretic Giordano Bruno, the techniques revolved around the creation (or perhaps calling up from some subconscious pre-existance) of a consistent interior "landscape", or often a building or large edifice of some sort, that would be visualized in as much realistic detail as possible, then decked with assorted metaphorically suggestive visual images, to represent the information intended to be stored. In this way extremely dense and detailed accumulation of facts and their interrelationships could be represented, not in a voluminously cumbersome verbal form, but in the far more easily recalled context of the arrangement of something similar to scenes from a play, often exaggeratedly bizzare or unusual to accentuate their memorability.

To recall information stored this way, one would mentally "walk through" the rooms and other areas of the house, garden, temple, or whatever setting had been chosen, and observe the scenes, allowing them to call to mind what they were selected or designed to represent.

Although it could be seen as superfluous in modern times, when demands on unaided human memory have been significantly reduced by the conveniences mentioned above and others, this exercise, while a bit of a chore at first, has been revived in practice by some who claim for it a more than merely practical utility. I've often thought this could be one helluva VR killer app, as well. Great, now somebody else'll get to it first. Oh well, send me a copy?

Essays and offerings on the topic by John Michael Greer, and others, are at http://www.gothitica.com/memory/articles.html