The "SEE ME" light belt for runners, cyclists and walkers is an array of bright LEDs with the text "SEE ME," based on the premise that simple text is easier for motorists to interpret than other, non-text symbols such as arrows.
According to SEE ME's creator, the message is sharp, personal, and brief and flashes interrupt the distraction of even a cell phone user.
The electronics are in a waterproof housing and used as a belt that you wear around your waist. AA batteries provide power.
More details and ordering info from See Me.