Just how far will a WiFi or wireless internet signal go? Can you believe 310 Kilometers? The for the longest WiFi link, 310 kilometers belongs to Alvarion and The Swedish Space Corporation. The previous record was over two hundred kilometers across the Great Salt Lake In Utah.

The super long range WiFi link was made in 2002 between a stratospheric balloon that was launched from Esrange near the town of Kiruna in Sweden and a base station located near Esrange.

Granted that the system used a 2.5 meter parabolic dish, about the size of the old type satellite TV dishes and a high powered adapter it was an amazing feat.

How far can the average person obtain a wireless internet connection from, say a neighbor's home or other access point?
It depends on the Db gain of the directional antenna, the power of the wireless adapter, obstacles in between, and the power and placement of the router antenna at the other end.
It helps if there are no buildings between you and the WiFi signal you are trying to capture.
It also helps if your home is located on a hill above a town.
Getting the WiFi antenna as high as possible is best.
2.4 Ghz, which is where WiFi operates is in the microwave end of the spectrum. It will travel through walls and trees but you will lose some signal.

While you may not be able to have any control of the wireless antenna you can increase the gain of your receiving antenna. The highest gain 2.4 Ghz WiFi antennas on the market are grid parabolic, followed by Panel and Yagi type antennas. Panel antennas are low profile and can withstand high winds and the elements.
I have personally been able to establish as good WiFi connection with an RV park that is located ten miles from my home using a panel antenna and an Engenius brand WiFi adapter. For more on how I did it see the following article:
http://ehelpfultips.com/how_to_get_free_internet_with_lo.htm