I would love it if there were the ability to essentially "paste" notes onto a sketch, perhaps associating them with some object in the sketch. I would often find it helpful to give "names" to different parts just to refresh my memory of what they are. For example, I'm building a finger for a robot hand. Each finger has three knuckles, and I'd love to be able to essentially visually label them as Knuckle A, Knuckle B, and Knuckle C. And explanatory notes would be a great help as well.
