This is a fun little book on heuristics for improving memory, mostly "short term", which basically amount to mapping pieces of the thing[s] you want to memorize (phone numbers, sequence of objects facts etc.) and the relations between these things to another "context" that is more familiar to you (e.g. letters to people you know, foreign words to objects that sound similar to words in your native language etc.) and then purposely exaggerating the context you've mapped the information to make it stick out in your mind.
Dellis, who is a memory champion litters most of the book with examples of this process, and many of his "context mappings" (my phrase) tend to be absurd, surreal, or down right grotesque (toilet humor a plenty in this book). Still, I appreciated the practical nature of the book, it's a text "light" on theory, and very much designed to get you executing on improving your memory. Though Dellis has a named-system for this process, it actually escapes me at the moment (ironic!), so I'll have to definitely listen to the text again (or perhaps purchase the kindle version as visual contextualization is a big part of his process, and from what I can tell, his book has a lot of interesting info/process visuals to help digest and internalize his system.
A definite recommend, perhaps not in audiobook format alone, but I think it would be worth getting both the audio and kindle for this one. I'll update my review once I've gone through it in Kindle format.