Ron White of Fort Worth, Texas has a lot of 'mental muscle'. The Navy Vet recently won for the second year in a row the annual USA memory Championship. Some of events included memorizing the names of 99 people and their pictures, a 50-line poem in free verse and over 100 single numbers in the right order.
Ron now prepares for the World Championships in China in November and should do pretty well - right now, he can memorize the order of a deck of cards in just over a minute.
For more on Ron and his techniques, check out his website.