This guide describes it's uses and explains how you can easily make your own for cheap.
A Proof-of-Concept acts as a single point-of-connection that allows you to use an existing wireless signal to provide an active internet connection to any or all of your 'internet-friendly' devices. It can be used to provide free internet to your home if there are public (unencrypted) wifi signals in the area. It is illegal to connect to a private/encrypted network without the owners consent however public/unencrypted networks are legal and free to use.
The guide is rather long and includes a number of images and screen-shots so here is a direct link to the full guide and additional information : http://allianceonline.info/poc
http://allianceonline.info/poc
I have also attached diagram to display how it works.















![D-Link Wireless Router DIR-628 Setup [Without CD]](http://img.instructables.com/files/deriv/FDQ/ZBHK/GIYWWBMF/FDQZBHKGIYWWBMF.SQUARE.jpg)



















http://www.law.cornell.edu/uscode/18/1030.html
Like this fella a while back
http://arstechnica.com/old/content/2006/03/6447.ars
Chances of getting caught are tiny, especially these days, as just because I'm sitting outside someones house surfing the net on my laptop doesn't mean I'm ripping their signal, I use my android phone to wifi tether these days.
However you are giving legal advice when you really shouldn't. And with that I advise anyone reading this to find out the applicable law for their region. I'm not a Lawyer, and this post isn't legal advice!