Acceptable:

Text messaging bicycle

Frowned upon:

Bluetooth earpiece

Only if you're a billionaire, and even then probably not a good idea:

Google glasses Sergey Brin

Please, no:

MH2 Shoulder Robot

The MH2 Wearable Humanoid Robot, developed by scientists at Japan's Yamagata University, "lives on your shoulder and can be remotely inhabited by your friends from anywhere in the world," according to Evan Ackerman at IEEE Spectrum's Automaton blog.

 

Photographs by Mo Riza, Ed Yourdon, Thomas Hawk and courtesy Yuichi Tsumaki, Fumiaki Hono, Taisuke Tsukuda/Yamagata University.