If you can wait a year...
A new device was launched recently (IXI Personal Mobile Gateway) which uses blutooth to network a variety of devices (phones, watches, videos, MP3 players etc). Sanyo and Samsung are the first to perpare compatible devices and the first of these are expected on the market late summer (IT speak for next year)..
...so no wires and a bluetooth earphone the size of an earlug is already available (Bluespoon)....
Dick Tracy's dreams have come true
The lady attached shows some of Sanyo's credit card sized items...