Build a Raspberry Pi-Powered Linux Laptop That Fits in Your Pocket | Make:. Why would anyone use the tiny Pi computer ($35) and a Nintendo DS case, and a tiny keyboard to make a fully functional handheld computer? Because he can. Using the Linux OS (free), $120 worth of parts, and some time and ingenuity, this guy did it. You can even output the video to a full sized monitor if the tiny screen is too much for your old eyes. Very cool. Very geek.