I absolutely love Sephora's refillable powder brush.
It's the perfect solution to messy mineral makeup and loose powder. The container is incredibly easy to fill - the bottom unscrews, use the included mini spatula to spoon your powder into the vessel, snap it all back together and voila! You're in business. It comes with a cap to keep the brush clean and fluffy; and the bottom twists open and closed so you never end up with powder flying all over your purse. Love this! Get one! $24 in store and online.