1. A non-transitory storage medium having stored thereon an information processing program executed by a computer of an information processing using acceleration data outputted by an acceleration sensor that is configured to detect an acceleration, in at least one axial direction, applied to a predetermined housing thereof, the information processing program causing the computer to function as: repeatedly acquiring the acceleration data; calculating an accumulation vector by sequentially accumulating an acceleration vector having a magnitude and a direction of the acceleration represented by the acceleration data, thereby providing a calculated accumulation vector; calculating a following vector which follows the calculated accumulation vector at a predetermined rate, said following vector calculated using a calculation which includes the calculated accumulation vector; a differential vector as a difference between the accumulation vector and the calculated following vector; and designating a position in a virtual world using a value determined in accordance with the differential vector, and performing a predetermined processing by using the position.