You're probably on camera right now. Wave hello. If you were wearing this line of Cold Flare jewelry from a pair of ITP students, you'd be invisible—or at least, anonymous(er).
Embedded in the jewelry are high-output infrared LEDs, which cause massive lens flare in surveillance cameras—particularly the kind designed to see at night. The result is that your face is effectively obscured from most angles on security cameras. You're still totally visible to the human eye though, since the light doesn't really affect our field vision. [ITP]