Reading this blog just reminded me how much I love the Moleskine notebooks–they’re small enough to stick in the front or back pocket of your jeans, the hard cover makes them easy to write in, and the little pocket at the back of the book is great for holding little slips of paper and stuff (like receipts when you’re traveling). My favorites are the square-ruled ones, since the grid makes for easy class diagrams, but the straight ruled notebooks are good for notes and ideas, too.
My friends all tease and chide me that I need to get a PDA, but frankly, I *like* having paper notebooks for some reason–maybe it’s the connection back to historical roots, or perhaps it’s just the idea of not having to worry about battery life. Regardless, I’m not giving mine up any time soon.
(Borders and Barnes & Noble also have some larger notebooks that are square-ruled, both in the Moleskine-size, as well as a more 5×7-ish size, which is my current "bible", as I’ve mentioned before. They’re not quite as nice, but they also serve the same purpose. Call me old-fashioned, if you will, but there’s just something still really enjoyable about writing with pen on paper.)