Using an empty coffee can, a wire hanger and a couple of cheap technology accessories, author and handy geek John Graham-Cumming built this simple wi-fi antenna for around $5. The antenna is directional, long range and very strong - all for almost no money and with very little need for technical knowledge.
The entire materials list and instructions can be found at the inventor’s blog. He points out that the shape of the can and the fact that it has a lid are both helpful facets of the design; when the antenna is not in use, the cord fits neatly inside the can. Little details like the size of the can and the positioning of the elements all have an effect on the strength of the antenna, so it’s worth following the instructions to get the best result.