I am curious though how it would be regarded legally if someone used Kismac while traveling to see if there is a network around and happened to find a network with WEP turned off and then used it to reach the Internet for some light duty (low data volume), legal web surfing or email checking without checking whether the owner intended to share the network (or was merely incompentent to not secure his network).
If the network is unencrypted and wide open (not restricted to certain MAC addresses), and the SSID is something like "public" or "open" or something else equally obvious, I don't think there would be a legal problem.
If the network is restricted to certain MAC addresses, the SSID is not broadcast, or is WEP encrypted (i.e., they have taken some sort of measures to protect themselves against casual WiFi surfers), I think you'd run serious risk of legal liability.