Noticed on this trip that there is a special immigration program which allows you entry into the UK without speaking to an immigration guard. I think this is in Terminal 2.

You line up and then go into this little booth and stare like a maniac into a lens. Then it says (in a loud robotic voice) "Move closer" or "Move down" over and over again until it tells you that your eyes can not be scanned and tells you to go all the way to the back of the regular entry queue(!).

..or at least that is what happened to a number of people I saw that day.

It was comically pathetic.