cheap and nasty Wifi Antenna design
A lot more has been said than written about the legendary Pringle's Can Wi-Fi antenna, and a lot more people have talked glowingly about them without ever actually using one. Look closely, and you'll see that you have to add various things to it to make it work even so-so. Unless you have a can with a foil lining (not all Pringle's cans that I've seen do) and unless you can make good electrical contact to that foil lining (not a slam-dunk, trust me!) the can won't act as a waveguide antenna and thus won't throw your signal very far or bring in anything from a distance... Don't obsess on the Pringle's solution. There's an easier kitchen-trash antenna to be had: The Tetra Brik Soup Box.
C'mon, you know you've thought about it -- no, not what you'd do if Natalie Portman actually answered your fanboy emails -- building a Wi-Fi antenna from one of those in-pot steamer/strainers (a Hollywood favorite when depicting junk-built robots and various McGuyver hacks). A builder on Instructables has done just that, creating a signal booster for a thumb-drive-type USB Wi-Fi Adaptor. Making such a uni-directional booster is actually very easy, and at least according to the builder, significantly boosts signal strength.