Max Körner (1883-1963), who I wrote about two weeks ago, left behind more than a bunch of obscure trademarks. Thanks to Daily Heller private eye and public nose sleuth, Mirko Ilic, we see (below) that Bluetooth owes a rather obvious debt to this less known German logo designer for his 1922 Behinger and Co. original.
For more Steven Heller, check out The Education of a Graphic Designer, one of the many Heller titles available at MyDesignShop.com.