Wacom Pen Partner 2

For a flat, black panel of plastic, the PenPartner 2 looks surprisingly slick and would be extremely easy to carry around with your laptop

Even though setup and tweaking is as basic as it comes, you are going to be using these features a lot ; the device is (justifiably) so small that it takes a bit of getting used and for the first few minutes you'll be drawing squiggly lines all over...