Do they work or not if they work how far? Anyone got one? Anyone build one ! I got some parts to build one a few years ago from a friend but I never got around to it !
I have three of these sitting around to build some but never checked in any farther


Here is a Cantenna how to ! Clicky
I think they look too cheap to work ??? But ya never know !
Then they have a fancy looking one for sale here ! Clicky
I've never made one but I've heard and seen alot about them. I've seen them made of Pringles cans and empty coffee cans. Those do work, but they aren't very good. The 'professional' ones are much better. They're great for wardriving, and trying to pinpoint where exactly a wifi access point is coming from. And also if you're wanting to steal, borrow, security test someone else's wifi. 
If you end up making one as an experiment, I'd LOVE if you documented the whole thing and posted it all here. Making it, using it, etc. 
I saw a nerf gun while at Defcon that had pringles cantennas. It was bad azz..


The guy was super cool and he was using it to help raise money for a great charity: Hackers For Charity anyways the guy has more pics and the specs for his gun here: Building Vera-ng

Wellington Florida
Married
Ok I have to admit that is cool. See that would be a fun project for my kids over the summer. I'm now curious as hell if it really works. Hell that probably could have saved me some money too. The way my house is built (in Fl. most houses are built out of Cement blocks) I have issues sometimes with my wifi reaching the whole house. I had to buy one of these boosters to help. Now I wonder if I could have used one of these.