Iridescent cloud perhaps? (google it!) I saw something similar above St Andrews a few years ago and the weather conditions were unusual; bright sun, extremely cold and very windy.
Was doing a bit of christmas shopping with the OH yesterday and saw a huge crowd of people with cameras pointed skyward. Though "what a bunch of eejits" then looked up and took a snap myself Pretty cool looking.
NO WAY, just saw this thread. I saw the same clouds yeah and took pictures of them. I'll post them up later although they look pretty much the same as what people have already posted.
