I just built (well, my girlfriend and I built) the pringles yagi antenna as per the page at http://www.oreillynet.com/cs/weblog/view/wlg/448
I didn't think it would work at all, but it works great. I can 'see' FIVE different APs just pointing this thing out my window, and was even able to associate with two of them. I have it sitting on a tripod with a 1.5m pigtail from WirelessSupplyGuy. I'm glad I have this length; anything shorter would be a pain.
By cutting the right size hole (I traced the inside of the nut on the N-connector onto the pringles can with a pen) I was able to screw the N-connector right into the pringles can. My girlfriend's small hands were able to reach in and lock the connector in place with the nut.
We did a really half-assed job soldering the copper wire to the connector. I want to re-solder it with copper solder.
We cut the aluminum tubing using a ruler that only went down to 1/16th of an inch and a dremel tool. We wore protective goggles, and you should too! There were bits of aluminum flying everywhere. The dremel cut through the tubing like butter at its highest speed, but it is really hard to get a nice straight cut. The cuts have to be really straight so the whole thing so the tension between the washers and tube sections doesn't cause the whole thing to become bent. Our solution was to cut a bunch of sections and then select the best ones, based on their length and how straight they stood when we stood them on the table. (now you know why I said I didn't think it would work at all.)
Update: I rebuilt the antenna after buying a tube cutter. This made the cuts MUCH cleaner and more accurate. It cost me about $5, but was worth it. I'd be very happy to lend it out, just email me, patrick at nameboy dot com. The thing looks like this:
We screwed the whole thing together gently with the n-connectors. I just made a mark where it all fit together and we cut it there. Beware sparks from the steel allthread! goggles are a must.
The tripod helps a lot.
I am posting pictures on the wiki.