The JR East Pass Special is a very economical ticket that can be used for a limited time between Sept. 1 to Nov. 30, 2010. With this pass, you can freely get on and off JR East Shinkansen, limited express, and other trains all you want. It is available for three days of your choice within a ten-day period. You get unlimited travel on the Narita Express connecting Narita Airport and the Tokyo area as well as Shinkansen and limited express trains to Shinshu (Nagano), Nikko, Sendai and Aomori. The JR East Pass Special is even available for travel on trains other than those of JR East going from Tokyo to Izu, Naoetsu and the Nikko area, as well as trains in the Shinshu (Nagano) area.
While in Japan, take advantage of this special offer to see a lot more for a lot less.
For details : http://www.jreast.co.jp/e/eastpass_sp/