Be aware that, in the U.S., if you are using a Wifi access from an "open or not" hotspot, make sure that the owner of the hotspot knows and give you permission to use it. As for the person providing that access, make sure they are allowed to "provide" the access. That means that if it is from home, make sure it doesn't go against the ISP's TOS(terms of service). I'm looking of some court cases where people may have been slapped with a felony for "theft of service" using a high powered antenna or similar.