Blindfold chess is certainly effective for improving your spacial memory, but why leave it at that? I highly recommend anyone and everyone learn the memory palace technique (http://en.wikipedia.org/wiki/Method_of_loci), which takes advantage of the fact that our spacial memory is vastly superior to our memory for facts, allowing anyone to develop the functional equivalent of a photographic memory. In Moonwalking with Einstein (a really fun and fast autobiographical tutorial on memory), the author Joshua Foer explains how to encode facts into images and then arrange them along spacial layouts to maximize the brain's potential. In convincing my mother to read the book, I had her memorize a 10-item shopping list in about five minutes when she was incredibly tired (which is when her memory and general thinking ability are at their absolute worst), and she still remembers all ten items, in order, to this day.
