Even if you could carry a stable connection that distance, I'd be surprised if you could make any good use of the high speed they have. Plus of course, institutions such as libraries are far more likely to have encryption than the average home.
To Sammorris: Well the local library branch offers free wi-fi internet for anyone with a wi-fi connection but once you walk out the door the connection strength falls down to about 30% and if you are about 12 yards away the strength falls to about 5%. A lot of public library systems around the country(USA) offer free wi-fi.