Net seeker

So, I've been thinking about this for a while now: Why isn't there a TRUE WiFi finder dongle thingy (is there? I've never heard of one...) What I'm thinking of us not simply something which senses the existence of a wifi signal, but finds and tests open, unlocked WiFi 'automatically.' Basically, I'm thinking of using a wifi module tied to an 8-bit micro with a push-button and a tri-color LED as a status indicator, running off of whatever necessary battery source (Recharable LiIon via USB?)

It would work something like this:

Push "Search"

hacking the wireless

We have three wireless routers in the house but we are not using them to the full advantage. The first one is called "Tyler Durden", the second "Life Is Too Important To Be Taken" and the third one is a Fon-hotspot. The ideal would be that we use one or two of these routers to share internet, and since the Fon-router has a great antenna attached to it, this one would be perfect to share our internet with at least 50 households. There is however one big problem with this router.