If anyone is interested, I have done a lot of experiments using a 60cm satellite dish with a wifi antenna-and-receiver taped to the focal point, connected to my PC indoors via a USB cable. From my mountainside home I can always see about 10 wifi sources, but using the dish this doubles and the furthest source from which I could get a useable signal was maybe 15km away.
In Spain we are lucky in as much as every community provides free wifi (or free once someone tells you the password which is distributed to everyone living there) but also most bars, cafes, camping sites and marinas also off free or quasi-free wifi.
Thos of us with free time (or perhaps no wife), possessing some copper wire, side-cutters and a soldering iron, and a modicum of coax cable, will find plenty of useful advice on the 'net on modifying that spare satellite dish to boost a wifi signal.
Not me, I might add, as I have internet by WiMax.