you could also use cylinders. rotate them on the z axis, use the edit palate to resize the y dimention, rotate back until the bottom of the cylinder is parallel to the ground, move on the x axis away from 0, put the object's origin at zero, duplicate, put the new object on top of the first, rotate around y so the sides line up, and use the y offset and the rotation to multireplicate. the shorter the cylinders are the better the helix looks close up, but it also takes up more memory.