ThinkGeek's LED light mine works like this: when exploring lightless coridoors in distant abandoned space outposts, you turn one on and hurl it before you. One of its bristling crown of neo magnets will stick to something useful.
Because each LED Magnetic Light Mine is one super-bright, wide angle LED light surrounded by 12 stalks. Each stalk has a neodymium magnet on the end. Which means you not only can attach these lights to any magnetic surface, but you can aim the light, too.
It's $7 and needs three coin batteries.
LED Magnetic Light Mine [ThinkGeek]