We have many iPhone apps dedicated to store your bright ideas. But the iBlackBoard iPhone 4 case is the most convenient one. Of course, the precondition is, you need a chalk.
In fact, iBlackBoard is not a real product. Kalomix, a design studio from Hong Kong came up with the wonderful design concept combined with modern technology and traditional tool. From the images, apparently the iPhone 4 case is painted with black chalkboard paint so that we can use a common chalk to write down some important things on the exterior of the case. After the break, check out the demo video.
Unfortunately, this is only a design concept. Even if you need, the fun iPhone 4 case is unavailable at present. By the way, perhaps someone can design a matching iBrush iPhone 4 case. Sound good!