The Vivitar Deluxe Power Grip for Nikon D5000 will power a Nikon D5000 camera on 2 EN-EL9 batteries--the grip helps maintain stability when holding the camera, provides extended shooting time, and has a vertical grip shutter release button that makes switching from horizontal to vertical framing a snap.
Provides extended shooting time
Improves stability
Vertical grip shutter release button to enable shooting in the same frame as a horizontal grip