The invention provides toner cartridges that deliver toner in a metered fashion to an image forming apparatus. The cartridges have a delivery mechanism comprising a toner delivery member that delivers toner to the supply port as it is rotated. Depending upon the orientation of the delivery mechanism, the toner delivery member can at least partially block or at least partially allow the free flow of toner out of the supply port, as desired. The delivery mechanism of the invention can be used to deliver toner, developer, or any such powder out of a container.