You know I love a gadget! I have had my eye on this in Muji for a while. Last time I was in there they had one out to use, this meant I could try before I buy - LOVE that! It is a punch but it doesn't punch a whole hole it cuts a flap for want of a better word.
I have a notebook that I use for writing guest posts and blog posts, I had been using cute little postit notes but found they would often fall off in my bag, not an efficient system! With this gadget I can make little flaps. I have them punched on every page then when I have finished writing the first draft, I turn the flap up.
Then when the article/post has been published I turn the flap down again. This way I can keep track of where I am up to and not lose posts that I have drafted then forgotten about. I always carry a notebook with me when ever I leave the house, you never know when inspiration will hit or when you are going to be stuck waiting somewhere with nothing to do.
I have, on occasion forgotten my purse but not my notebook! Oh yes, and carry 2 pens just in case one runs out! Do you have a handbag essential that most people don't carry?