RFID tags are used for everything from credit cards and passports to inventory control and door locks. Everyone should know more than a thing or two about them. With this guide you'll be able to learn how to read, "spoof" and use RFID in both common and creative ways. Their ubiquitous nature and how little an average citizen knows about them also makes for great science fair and educational projects. So, have a look at some of what Instructables has on offer!