Another detail you'll notice about the ThinkPad Tablet is that it looks as if someone drilled a hole into its side. Lenovo has smartly integrated a cubbyhole into the side of the tablet for holding an optional digital pen accessory. What's more, there are holes in both the pen and the tablet that allow you to attach the pricey pen ($39.99) for safekeeping. It's the best design we've seen yet for those who need regular access to a pen digitizer. If you don't plan on using the ThinkPad Tablet with a stylus, Lenovo includes a plastic cover that plugs the hole.