Children of Mana for the Nintendo DS is available for $17.99 (40% off).  It is the Amazon Deal of the Day for Tuesday, April 17, 2007.

Check it out:  Amazon Deal of the Day

Product Description
Children Of Mana takes us back to ages past, when an island called Illusia floated at the center of the world. At the heart of the island towered an ancient, enormous tree that stretched up to the very heavens. When a time of darkness comes, chaos and sorrow engulfed the world until at last its salvation appeared - in the form of a boy, a girl, and a holy sword.