In the 1990s, Bluetooth was invented in a lab in Lund, Sweden.The technology is used today to wirelessly connect accessories such as mice, keyboards, speakers and headphones to desktops, laptops and mobile phones.It’s named after Harald Bluetooth, a Viking king who was said to have blue teeth.Sven Mattisson, one of the brains behind the technology, tells Gill Kearsley how the name Bluetooth came about following some drinks after a conference.(Photo: A mobile phone with the Bluetooth logo. Credit: Westend61 via Getty images)