Do you know about those legendary notebooks you can buy at Barnes & Noble as touted by the late author Bruce Chatwin? They come in several sizes; the pocket size (just a tad larger than a 3 x 5 card) is perfect for a breast pocket or cargo pants pocket. The paper is acid free and rich enough to take ink, so you can sketch as well as take notes, but the most useful feature is the elastic band (which is a built in bookmark) that holds the notebook together -- you can stuff business cards, clippings, sketches on napkins between the pages, and the rubberized cloth thing holds them all together until you can find a place for the scraps. I've carried mine literally around the world.