Not quite the first...
Globalsat has had a set for a year or so -- http://www.globalsat.com.tw/eng/product_detail_00000061.htm
Congratulations to Etymotic for creating Ety8, the world's first Bluetooth in-the-ear earphones - the antidote, it reckons, to the bulky Bluetooth cans we've seen on the market to date. Ety8 Got a light? The earphones are compatible with dockable iPods - for which a transmitter is supplied - and Bluetooth-enabled mobile …