Paper circuits are all the go at the moment because they are fun for making light up cards. It is also a very straightforward and simple introduction to circuits and electronics. The video explains clearly the logic behind what you are doing and then you can see that it is not that hard to do. Copper tape, 3V batteries and little LED lights are not that hard to source and then making the card adds something creative and personal to the process. If you prefer written instructions you can find them here on Hi-Low Tech .