A great payphone hack would be to make it a dead-drop. Ie: put in a hard drive and a usb port and small controller. Then plug in your usb key, dial a number, it

A great payphone hack would be to make it a dead-drop. Ie: put in a hard drive and a usb port and small controller. Then plug in your usb key, dial a number, it gets copied to the HD. Next person to insert his key and dial your number gets the data you copied.