The I/O Brush is a conceptual design brewed up from the students at the MIT Media Lab. The idea behind the I/O brush is to turn the world into a palette. You can use the brush to pick up textures, colors and patterns from anything and then paint it onto a digital canvas.
The technology inside of the brush itself is pretty amazing. It has a camera, lights and touch-sensitive optic strands. When you place the brush on an object, the strands will sense it and turn on a light to give the camera a clear picture of what object you are trying to pick up. Then it'll take a snapshot of the object and store it in internal memory. When you're ready to paint, it will recall the image and "paint" it onto a digital canvas — sort of like a real-world version of the Photoshop cloning tool. The speed and pressure of the strokes can also modify how the digital painting will look.
This is an interesting, high-tech take on traditional artwork. While I don't know how feasible it would be for professional artists, the I/O Brush could be a great learning tool for children in art classes and such… that is, if it ever becomes a real product.