I hate all these analogies! I always look for a signal on my axim. I haven't had the need to on my lappy unless at a friends house, where they set me up anyway.
If someone is broadcasting a signal, the way the FCC law reads is that it is not against the law to recieve the signal if unsecured (i.e. not a police frequency, etc.) However, it is against the law for you to use networking equipment that you do not have explicit permission to use. Thus, using a neighbor's AP without their knowledge is breaking a Federal law. If they give you permission, they are breeching thier contract with the ISP, and that's between the ISP and your neighbor. As for that court case, I've not heard of that one before but I'm gonna look it up.
Know what you're up against before you break the law. Chance are you won't get caught, but if you do...you don't want to be the example do you?
http://www4.law.cornell.edu/uscode/h...0----000-.html
see section A(2)