This is a new phenomenon becoming popular in densely populated areas such as planes; trains and other public locations mostly in the UK. It is basically a form of anonymous sex. How it works is you enable Bluetooth on your suitable device; discover other Bluetooth devices and send them your business card with an invite, something like “Toothing?” You then swap your vital info’s and agree on a location to do “the deed” (which is anything from, presumably, coffee to sex...