The blue tooth headset that is often seen sported by people walking down the street, in a coffee shop, and in client meetings. Often associated with those who think they are so cool that they can't take off their blue-tooth headset, thus rendering them a Blue Doosh.
Typically a douchebag who has a Blue Tooth headset on.
*looking at someone sitting at the table next to you in a restaurant, with his left ear flickering*
"Blue Doosh alert! That guy is wearing his Blue Doosh."