[tasogare]

The post is not uninteresting but I doubt it has any real life applicability. Memorizing the number->consonants mapping (which is lossy) probably take already more time and efforts than memorizing the few raw digit strings that much be memorized in one’s life. It also assumes people would recall accurately a phrase or sentence.

My personal technic for memorizing numbers like pin or phone numbers is to memorize the general shape of the difference between each digit. It’s obvious to compute, use visual memory and doesn’t not requires an external system.

[Smaug123]

I use Major for dates, and I know the periodic table as a mapping of number <-> element <-> symbol. (And, by accident, I know my Oyster card's serial number.) It also is handy if you want to carry a number around briefly without writing it down - I've used it for carrying numbers from computer to computer at work. With lots more practice I could probably get near-real-time memorisation, and the possibilities would expand much more.

[progfix]

These techniques are useful when you need to memorise a lot of information. It takes a lot of training to work with the system in a reasonable speed.

[TheMightyLlama]

Could you explain that further? What do you mean the general shape of the difference between each digit?