Folks - the subject of 'noise' in an image is as vast as the universe - well, nearly.... All CCD's will generate noise. As well as that, your optical setup will contribute. A lot of noise is due to thermal effect within the CCD - hence cooled CCD cameras for advanced astrophotography.
I don't know if standard advanced CCD camera techniques will work on webcams and digicams, presumably it will - a CCD is a CCD... However, given the lengths you can go to, its probably of limited value.
The best place to go for advice is the net - or buy an astrophotography book (Ron Wodaski's is superb). look up dark-frames, flat-fields and bias-frames.
Software (Photoshop etc) will *not* remove noise in the true sense of the word. It will remove visual imperfections but only by changing the data (brightness, contrast, sharpening etc). But if the software makes your image look better, then go for it and forget all about flat-fields etc!
Dave
  