Items, including lost items or items out of place, can be located by attaching flickering LED's to them and moving about with a detector that registers the presence of the desired item or items by decoding the flickers. The flickers can substitute for, or augment, ordinary printed bar codes, and can use the same encoding so that the temporal pattern of flickering corresponds to the spatial pattern of black and white stripes in the printed bar code. The flickering items can be registered from a distance and from among a large group of other flickering items.