Just stumbled upon this website. I captured the images below a couple of weeks back, I had no idea at the time what they were. On Monday BBC Radio 5 Live were discussing being able to see NLC's and their description was exactly what I had taken pictures of.
All photo's were taken on the 14/07/2009 between 21.55 and 22.00BST.
Thanks for the link, I will make a note of the detail next time. When I first saw the NLC I had no-idea what it was and just grabbed the camera. It was only by chance the I heard NLC mentioned on Rhod Sharp's "Up All Night" show between 1am - 4am Tuesday morning Here is a link to the listen again on BBC's website - www.bbc.co.uk/fivelive/programmes/schedules/2009/07/28
I think NLC was mentioned 30 minutes into the show - World Weather with Philip Eden.
They spoke about NLC at some length and how we are not sure how they are created or where they come from - space dust or volcanic ash from a recent eruption in Russia.
I will be keeping an eye out for more NLC and I will pay more attention to their characteristics - now that I know more about what I am actually seeing!