DIGITAL faces. Digitised faces. Morphed faces. Composite faces. Face transplants. Working out what a face signifies is an increasingly complex matter in a world where an archive image of Hitler is grafted onto an actor, a digitised Marlene Dietrich makes a comeback in a new film, and Michael Moore grasps George Bush in a wholly improbable embrace.

In a relatively short space of time, we've become de-sensitised to the carefully lit, manipulated and touched-up faces we see in newspapers and magazines. Computer-assisted facial animation, virtual reality and online avatars have prepared us for another layer of unreal reality. The combination of advanced biometric techniques, encoding facial characteristics, with photographic and moving image enhancement, has both improved media images and enabled the technology of facial identification to be used in forensic science and security systems.

Above all, is the ubiquity of these changes preventing us from noticing them properly, and considering ...