This is a stack of over 150 images with 50 seconds exposure. Thanks to CHDK I used an interval meter script. Exposure time 50 seconds. Aperture f3.5. ISO 200. Review, off (important) Noise reduction, off (important) I shoot in raw, because it makes doing the dark frame subtraction easier. Software I used: UFRaw and Photoshop.
The linear trails in the sky aren't shooting stars: simply airplane tracks.