Mirror

Small mirrors make excellent reflectors for all kinds of outdoor shots, including portraits and close-ups, but who wants to carry a sheet of glass around all day? Yikes! Acrylic mirrors are relatively lightweight and totally indestructible (they'll outlast the backpack you carry them in) and you can usually find them cheap at your local drug store. Mirrors are super-efficient reflectors and highly directional, good for opening a deep shadow area or creating a bold fill, in a portrait, for instance.