here’s a guide for making an antenna for your access point that beats the pringles can on a number of fronts. it’s easier to assemble, requires no pigtail and no modification to your ap, and it is claimed to have better perfrmance characteristics.
the reflector design was originally intended to increase privacy, but the nice side effect is that it dramatically increases gain in the direction it is facing:
power normally transmitted in that direction is “bounced” forward. Therefore you have more control of where your signal is going when using this reflector. That feature of this antenna can be used to enhance the privacy of your wireless network and that was my reason for designing it in the first place, the rest is just gravy but it is very real and rather tasty gravy. :) Please also note that antenna gain is preferable to amplifier gain because it adds to both transmitted and received power.
the best part is that you can make one basically for free. grab some aluminum foil, cardboard, and a scissors and get to work.