Lifehacker found this one on Instructables, and it’s hands-down my favorite tip of the day!
“Parabolic surfaces are perfect for collecting errant wireless signals and focusing them, and the food strainer in your kitchen cabinet is a parabola waiting to do something other than hold pasta. Instructables user Dan Folkes describes how to turn an inexpensive Asian cooking strainer and an equally cheap USB Wi-Fi dongle into a signal-boosting dish. Dan boosted his signal enough to detect an additional 20 Wi-Fi hotspots using NetStumbler to sniff them out."