An embodiment of an organizer for a desk or other horizontal surface having an extending portion includes an elongated base assembly having a clamping member and a cover member for attaching to the extending portion, at least one fastening device for attaching the clamping member to the surface and for attaching the cover member to the clamping member, a pair of vertical supports adapted to be attached to the cover member and each support including a plurality of holes, and a plurality of horizontal accessory supporting rods extending from the slots in one of the vertical supports to the corresponding holes in the other vertical support.