I just discovered this little Nintendo DS Lite application last week where you can train your brain in minutes a day so that it will not be as idiotic as before, LOL! Well, the application is cool, Brain Age, as what they named it, is quite addictive. After playing with it in 3 days, my DS Brain Age is now 33 (compare that to 80 when I started using it!) They say that the ideal DS Brain Age is 20.
Here are some preview/trailer/teaser of the Brain Age 2 in Youtube:
If you are using R4DS and you are looking for its ROM version, the full version is already available for download here. Download at your own risks.