Where do you write down your ideas for programs, lists of useful libraries/software, approaches to solving different problems, articles to read later? Once in

Where do you write down your ideas for programs, lists of useful libraries/software, approaches to solving different problems, articles to read later? Once in a while I hear a programmer say they don't keep notes of any kind and I have to assume they were blessed with photographic memories and perfect recall, because the rest of us are not so fortunate.