My father always used to carry around a pen and crumpled pieces of paper in his coat so he could write things down—songs on the radio he liked, prices of things in stores, and other useless hunks of information. It wasn't very handy, though. Luckily for him, there's the PicoPad. PicoPad is a little credit card-sized (if not smaller) notepad complete with a minuscule pen for jotting down notes on the little blue sheets. It fits perfectly into a card slot in your wallet and doesn't get in the way at all. The paper included comes out easily and has a sticky back for using it like a Post-It Note. You can score a PicoPad for only $3.89 each in a multitude of colors. Extremely handy and a great gift for that dude you know who's always writing down numbers on his hand.
Product Page [Picopad]