Apologies, I'm using gmail on my mobile and it's not cutting me any slack at the moment
This tidbit here I think is the part you want I think...
"git rm --cached <file>" would remove <file> from version control, while keeping it in the working repository.
Alan,
also look at this...
http://stackoverflow.com/questions/936249/stop-tracking-and-ignore-changes-to-a-file-in-git