I wrote a three-part series of articles entitled "How to Build a Long-Range Wi-Fi System" that is still available with Part #1 starting at http://goo.gl/VpO8F. In that article, I described how I installed an external antenna on the back of my motor home that allows me to connect to wi-fi networks a quarter-mile away and sometimes even further.
In Part #3 of the article (available at http://goo.gl/IgkvI), I described the masts that I used. My first experiment was with a military surplus set of ten four-foot long fiberglass poles. That didn't work very well. The poles were big, heavy, awkward to install, and looked ugly. It got stares in the campground. I later discovered a telescoping aluminum flagpole mount made for recreational vehicles. Although it is described as a flag pole, this mast is perfect for use with a small to medium sized antenna on top! I use it for both my wi-fi antenna and for a television antenna that works a lot better than the one installed at the factory on the motor home's roof.
I even have my telephone service through the same wi-fi set-up, using a VoIP (Voice over Internet Protocol) telephone service. Not many people have phones sitting on the breakfast table in their RVs but I do and it works well in most, but not all, campground wi-fi networks. VoIP phone calls are much cheaper than using cell phone "minutes." The flag pole installs in seconds and seems to "blend in" nicely in an RV park.
The drawback with the telescoping aluminum flagpole is that they are hard to find. In the earlier articles, I did tell where I purchased mine: from a mail-order ham radio dealer. However, I noticed in the latest Camping World flyer that the big chain of camping supply stores is now selling the same thing. This should simplify purchases by RV owners, most of whom are very familiar with Camping World's many locations around the country. You can also purchase the same item by ordering online at the Camping World web site. If you belong to Camping World's President's Club, you get a discount.
You can find the Flagpole Buddy for $89.99 at http://www.campingworld.com/shopping/item/flagpole-buddy/60115
Camping World also sells a smaller, lighter-duty flagpole kit at http://www.campingworld.com/shopping/item/universal-flag-pole-kit/34827 and bigger, more heavy duty flagpoles for higher prices at http://www.campingworld.com/shopping/item/portable-20-telescoping-flagpole/36113 and at http://www.campingworld.com/shopping/item/1-5-flagpole-kit/65211. I don't have any experience with the other models, however.