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
I have also attached diagram to display how it works.