iPad: If you're a sketcher, note-taker, or all-around paper lover who happens to own an iPad, download Paper from FiftyThree right now. This beautiful app gives you digital notebooks to capture all your ideas quickly and intuitively. And it's free.
Getting started with Paper is quick. Tap on a notebook and start sketching, writing or outlining quickly with the free drawing/pen tool. Swipe and pinch to move between pages in your notebook or switch notebooks (you can have notebooks dedicated to ideas, a journal, sketches and so on). Additional tools are available for $1.99: a pencil for sketching, marker for outlining, and watercolor paintbrush.
Whether or not you consider yourself an artist, this is definitely an app worth trying, since you can use it for quick note-jotting as well. You might discover it brings out your hidden artistic skills too.
Paper [iTunes App Store]