Simply sign up at one of the applicable airports before you next fly out of the UK, and you're ready to jump some serious queues.
It's a very straightforward process to sign up, takes about five minutes, and is open many other nationalities as well, I'm a Kiwi and got signed up no worries.
IRIS is operating at the following United Kingdom airports:
# all five Heathrow terminals
# Manchester terminals 1 and 2
# Birmingham terminal 1
# Gatwick North and South terminals
Sadly it uses Iris recognition which slows down the processing time at the booths. It would have been much faster, user friendly, and less obtrusive using facial recognition, but you can't win them all.
Can easily save you over an hour at times, and also allows you to keep your passport safely tucked away.
I'm sure there will be the usual big brother is watching whingers, but if they just queue up with the rest, I'll be happy to give them a wave on my way through.
Hope this helps a few people out there to eliminate one queue of the many we are now faced with when travelling.
Happy travels all.http://www.ukba.homeoffice.gov.uk/managingborders/technology/iris/