Found this on my travels the other day, thought it may have been of use to someone. Haven't had a play with it yet, as i don't have a tripod.
CombineZM - it's a free download just google it. Nice bit of software that you can use to stack images together, with minimal effort. I'm sure it can be done in PS, but this seems pretty easy.
there's a tutorial here:
Spoiler:
Hope this isn't a re-post
Bilbo - i'd like to see some of yor pics using this
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