This is what I don't get either. I have a passport that will let me get through these gates apparently - it worked for me last time I landed at Birmingham. Some space age machine shone a light at my face and opened a gate for me. But I have never knowingly had an iris scan in my life so unless the border agency has somehow got optical records from my optician I'm at a loss to know how the machine recognised me unless it's using some kind of face recognition technology based on a very poor passport photo that doesn't look very much like me any more?

Anyhow, the staff at Birmingham were determined to push as many of us through the machines as possible but it was no quicker than going through the manned gate.