I consider this a kind of "work in progress" as I've only attempted to photograph star trails a very small handful of times.. this is the most successful result I've had so far. I wasn't going to go hiking off to some picturesque spot in the dark without first making sure I could do it ok, so do please forgive the slightly mundane foreground, incorporating our chimney and a tree from our garden. This is the first time I've managed to get the polar star in frame and now I know how to recognise it hopefully it shouldn't be too difficult to find again when I try this somewhere more interesting

It was about a 10 minute exposure during which time some clouds blew over and reflected a little of the nearby light pollution.. I quite like how it divided the sky though!
I used the 400d on this occasion as the cable release for the 40d hadn't yet arrived by that point.