I got the idea from an optometric examination of my infant daughter. The Auto-refractor used in the examination emitted a series of beeping noises and blinking lights to draw the attention of my kid towards the device. Beeing a nerdy dad's kid she usually looks towards LEDs and the like. 

This and the fact that it is rather hard to get her to look in the direction of the camera got me thinking: would it be practical to have the lens of the camera surrounded by some blinking lights to get the attention?