Here's my latest 5 minute Wi-Fi booster hardware project.
I had some aluminum flashing laying around in the garage, and I had read about the beer can wi-fi booster and it seemed like a piece of the flashing could do the same thing and would be an even larger reflective surface than the beer can. Thus was born:
All I had to do was cut off a piece of the flashing (it is thin enough that ordinary scissors work) and flatten it a bit. It is curved enough to stand on its own on the shelf next to the access point/router.
The router is on one side of the house and everything that wants wireless is on the other, so the reflector is pointing toward the other side of the house, and the results are quite astounding. I get a signal that is almost twice as strong as I used to get over on the other side of the house. With a 802.11n connection I've transferred a 3.5 GB iso image in 3 minutes and a few seconds. That always took far longer before the reflector.