The Bluetooth SIG adopted the name in honor of the tenth-century Vicking king Harold Blatand (Bl�tand) nicknamed King Harold Bluetooth. He is known for uniting Denmark and Norway (the Bluetooth technology was invented in now Swedish Scania -- Denmark). Likewise, Bluetooth is intended to unify different technologies including computers and phones. The Bluetooth logo merges the Nordic runes analogous to the modern Latin H and B.
Nickname Origin
The origin of the Bluetooth nickname is believed to be either because Harold ate blueberries, which colored his teeth blue, or more likely, because he was dark skinned. When the Vikings encountered dark-skinned Arabian merchants for the first time, they referred to them as "bl�menn", literally "blue men."