Just read Moonwalking with Einstein by Joshua Foer and highly recommend it. Foer is a journalist who interviewed several participants in the US and World Memory Championships. He found it so interesting that he trained for and competed in the US and World games.
He describes the techniques (ex., elaborative encoding) which are fun to experiment with and actually work. Also the personalities involved are very interesting as well.
Book is well organized and very readable
I have always imagined that Paradise will be a kind of library.
- Jorge Luis Borges