The next step in war driving is to enhance the data you're collecting with location or geographic data concerning the access point or device itself. In the modern day, the collection of this data has been facilitated through the use of Global Positioning System (GPS) technology. Modern GPS devices can be attached to a system such as a notebook or laptop to the use of Bluetooth, USB, or even serial connections in some cases. If you intend to perform war driving with a mobile device such as a tablet or smart phone, it is highly likely that your device may already contain a built-in GPS that can be used to map access points.
If you are going to use an external GPS device it is important to note that not all of these devices are created equal. Some devices are able to acquire a satellite fix and location within a very short time of...