Moonwalking With Einstein, by Joshua Foer

This is the captivating (and true) story of how Joshua Foer went from covering the U.S. Memory Championships as a scientific journalist to a competitor at them in just one year. Along the way, he learned a great deal about how memory works- and sometimes, dramatically, doesn't. Though it does have tips on how to improve your memory, it is less a how-to book and more a fascinating look at the human mind and one man's journey of discovery. An Amazon Best Book of the Month.