To do some Toothing in Chicago, IL USA is very easy in the loop area. Near the Merchandise Mart is an L Station that the majority of all L riders have to go through. During the movement of trains you can try to send a preprogrammed message out to Bluetooth users. The sender has to be quick on the send, but if you sit there through rush hour, you are scanning around 67,000 cell phones in an hour. I have just found this website, so I will try and direct some people to it, instead of sending them my phone number.
