I think the clay notebook carving Sumerians would be pretty excited to see the impressive evolution of writing utensils. I ran across two examples just today.
The first innovation, called the BookMarker, is fairly simple and low tech but still very useful (so long as we're still reading paper books). It was designed by a former engineer at IDEO. It's a simple concept and I like it.
The second one is more high tech and super cool. The product is called the Pulse Smartpen from a tech startup based in Oakland, CA. It essentially digitizes what you write and hear, perfect for college students taking notes during lectures.