"Brain Training for Adults" is a DS game for memory improvement which is a hot seller for retireees and seniors. 

http://hosted.ap.org/dynamic/stories/J/ … 7-11-06-04

3.3 Million sold in Japan since May '05, and will be titled "Brain Age" when it comes to the US on April 17 '06.

And for some reason it's called 'Prof. Kawashima's Brain Training: How Old Is Your Brain?' when it hits Europe at the end of March.

Those sales figures are fishy.  I'm pretty sure Brain Training has "only" sold a little over 1.2 million in Japan through December or January.  Of course, Brain Training 2 sold over 1.5 million and Brain Flex sold over 1 million, so perhaps the quoted number is some combination of the three games' sales.

Anyway, I'm definitely going to pick up Brain Age when it hits the states to see what all the fuss is about.  Brain Flex (titled Big Brain Academy over here) hits the U.S. on 5/30, but I don't know if I'll pick that one up or not.

I love these.