A Japanese man has memorized the value of pi, (which is the ratio of a circle's circumference to its radius) to almost 84,000 decimal places. Pi is what is known as a "transcendental number" i.e. it has an infinite number of decimal places, but no repeatable pattern (like the less well known number "e" which is the base of natural logarithms) http://news.yahoo.com/s/ap/20050702/ap_on_fe_st/japan_memorizing_pi P.S. to which most of you are probably asking --- "Great, but why would someone want to do such a thing?".... Answer: "To impress members of the opposite sex"