The iPad is big and bright and beautiful, so of course you want to draw all over it with your fingers. To facilitate that understandable urge, here are a couple of high-profile sketch products.
Doodling or making quick notes with pencil and paper is so old school. Cheap. Dependable. Easy to use. Erasable. But old school. Enter the digital sketchpad/notepad. No wasted paper. Tree friendly.