I cruised a part of my neighborhood with my phone running WiFiFoFum on logging mode. Later I showed the results to a group of neighbors. Boy, were they shocked, 60 access points, one third of them running open, one third with only easily-brakable WEP.
And it wasn’t any sort of special hacking tool — just a phone with free software loaded. If I’d bothered to use a notebook with hacking tools I could have owned 2/3 of the networks in the neighborhood, and probably half the computers.
My Samsung Galaxy S has that capability as part of the basic load.
All I have to do is enable my wifi connection and it immediately lists all of the networks within range.