One of the biggest limitations of the AR Drone is its WiFi 802.11b signal range. Mheeli over at RCgroups.com has worked up a solution that bypasses the whole WiFi need completely and instead uses an RC Controller. If your looking to mod your AR drone this will require some soldering knowledge as well as some light programming skills. Check out his video below and if interested, his tutorial. You can order all your parts from me here
