After buying then winning a pi cam I thought I better get to work with it. Thanks to design spark.com who had already written a good script I was able to position the cam on the window sill from dusk to dusk taking a picture every ten seconds and over 9gb of pictures.
With mencoder and some terminal typing I was able to make the pictures into a time lapse which I have uploaded to YouTube with the above link.
My next idea is to take pictures and layer them on top of each other ie time lapse the sky but get to show every vapour trail over say 6 hours.
If you know how I can do that then let me know, can't wait for camping this year.