JEFA Tech now sells a ready to go connector for your can! It includes the radiator. No soldering required! http://www.jefatech.com/product/cnfbst
They also have a complete Cantenna Kit including a USB adapter to plug it directly into your laptop. It is the one pictured below.
Here is the link to it on their webpage: http://www.jefatech.com/product/USB-CANTENNA-KIT
The PringlesCantenna is an ultracheap Yagi-type directional antenna that can be built for under $10. The original Pringles Yagi was designed by Andrew Clap. You can find the that design at http://www.netscum.com/~clapp/wireless.html
Rob Flickenger at O'Reilly refined that design by containing all its parts inside the Pringles can, and claimed a 12dB (or dbi which one is the difference?) boost. Directions are at http://www.oreillynet.com/cs/weblog/view/wlg/448
Gregory Rehm modified the Flickenger design by correcting its measurements, see http://www.turnpoint.net/wireless/antennas/mypringles.html
Later Rob Flickenger at O'Reilly found that the coffee can TinCantenna is much better it is cheaper and easier to build. It pulled 16dBi, and requires no additional parts other than the connector, wire, and the coffee can itself. See it at http://www.oreillynet.com/cs/user/view/wlg/1124
Gregory Rehm posted the following observation about the Flickenger coffee can TinCantenna design on the mailing list:
1st, Rob puts his 1/4 wavelength radiator (driven element) 1/4 wavelength from the back. It should be 1/4 STANDING wavelength from the back. Standing wavelength is calculated from the diameter of the waveguide (coffee can) and the operating frenquency with a little formula. In any can, it'll come out to be much larger than 1/4 the free space wavelength. 2nd, The can diameter is much bigger than the optimum for ISM frequencies. A Hunt's spagetti sauce can is closer to right. The ideal diameter for a round waveguide antenna is around .7 the operating wavelength. P.S. Here's the formula refered to above: Wg = Standing Wavelength inside Waveguide in inches f0 = operating frequency in MHz fc = TE11 waveguide cutoff frequency in MHz d = diameter of round waveguide antenna in inches fc = 6917.26/d Wg = 11802.85 / squareroot(f0squared - fcsquared)
Results of a "Homebrew Antenna Shootout" performed by Gregory Rehm comparing various pringles can yagi and tin can waveguide antennae can be found at http://www.turnpoint.net/wireless/has.html
Also related to the PringlesCantenna is the CookieCantenna.
This link includes dimensions, theory, and a chart for the math impaired. The drawings are much clearer. http://www.saunalahti.fi/~elepal/antenna2.html
A commercial version is for sale at http://www.Cantenna.com
See also pistol grip for cantenna mobile operations and wardriving. http://www.binarywolf.com/249/