The Inkling is a "digital sketch pen" that allows you to draw or sketch on any standard piece of paper (a big advantage over Livescribe, which requires special notebooks) and automatically have a digital version created. The pen looks like a regular ballpoint pen, but is much more powerful than that. As you draw, sketches, mind-maps, or brainstorms all get captured, and are available just by connecting your pen to the computer. You can even create layers as you sketch, and edit drawings even easier when you get back to the computer. Files can be accessed in applications like Photoshop and Illustrator, or just viewed on the computer.
There's also a receiver that comes with the Inkling, which is likely how Wacom was able to avoid requiring special paper. The receiver clips to whatever page or notebook you're using, and requires an uninterrupted line of sight with the pen while you're working. It could be a little kludgy, as the receiver is fairly large and is one more thing to carry and set up when you want to work. Battery life for the system, Wacom says, is more than eight hours of working time, which is a good number, but still means you might want to carry a normal pen or the charging cable in case you have a full day's worth of sketching to do.