Got Bluetooth?

The name "Bluetooth" is taken from the 10th century Danish King Harald Blatand - or Harold Bluetooth in English. During the formative stage of the Trade Association a code name was needed to name the effort. Over an evening discussing European history and the future of wireless technology several felt it was appropriate to name the technology after King Blatand. He had been instrumental in uniting warring factions in parts of what is now Norway, Sweden and Denmark - just as the technology is designed to allow collaboration between differing industries such as the computing, mobile phone and automotive markets. The code name stuck.

In Jelling, Denmark a monument can be found in a church yard that celebrates both his achievements and those of his father the first king of Denmark "Gorm the Old". Interestingly this particular stone was lost for nearly six-hundred years after Harald had a small war with his own son, Sven Forkbeard, over control of the country. Sven "won" the argument (exiling his father in the process), and since this runic stone also glorified Harald, Sven had it buried. Only years later a farmer, curious about a large mound in his farm, rediscovered the stone.

The logo itself was originally designed by a Scandinavian firm at the time the trade association was announced to the public. Keeping to the traditions of the name, the logo combines the runic alphabetic characters "H" which looks similar to an asterisk and a "B". Look carefully you can seen both represented in the logo.

- Bluetooth.org

Scotch Tape

I found this fun fact on 3M's website:

Richard Drew invented the first masking tape designed to help auto painters to make two-tone paint applications, a Roaring '20s craze, neat and easy. Drew was eager to have the tape sampled by its intended customers. He brought a prototype roll to a St. Paul auto painter. The painter carefully applied the masking tape along the edge of the color already painted and was just about to spray on the second color when the tape fell off. The annoyed painter examined the 2-inch wide tape and saw that it had adhesive only along its outer edges, but not in the middle.
Annoyed, the painter said to Drew, "Take this tape back to those Scotch bosses of yours and tell them to put more adhesive on it!"

The name – like the improved tape it inspired – stuck.
Scotch is a trademark of 3M.