Moleskine - Small Squared Notebook
Most people have a PDA, a laptop, or a phone that'll hold information galore inside of it, but almost no one keeps notebooks handy anymore. Once you start carrying a moleskin around, you'll wonder why you didn't. It's great for jotting down numbers, overhead conversations, things to do, ideas, short stories ... you name it. I use the squared version that has grids on every page, but they make them in ruled and plain versions, and even have music and storyboard notebooks for the budding aritsts. It has a pocket in the back to hold odds and ends (I use mine for stamps and business cards) and an elastic band and bookmark keep everything in place.
This is a fine Acid-Free note book . This means all your writings and drawings will last longer. Artist for many years have been keeping notebooks of the fine quality Moleskine has to withhold precious treasures. http://www.moleskine.com/eng/_interni/catalogo/Cat_int/catalogo_museum.htm