In a lovely essay on being persecuted by the number 7 (link via Colby Cosh), George Miller presents (among other things) the concept of recoding to remember more stuff. There are some nice illustrations of how this works:

It is a little dramatic to watch a person get 40 binary digits in a row and then repeat them back without error. However, if you think of this merely as a mnemonic trick for extending the memory span, you will miss the more important point that is implicit in nearly all such mnemonic devices. The point is that recoding is an extremely powerful weapon for increasing the amount of information that we can deal with. In one form or another we use recoding constantly in our daily behavior.