Nod is a gesture-control ring that aims to make your finger the ultimate
  input device
From: TechHive - 04/29/2014
By: Jon Phillips

Nod Labs announced Nod, a sensor-packed, Bluetooth-connected ring that is an
input device, just like a mouse, keyboard, or trackpad. Slip it on your index
finger. Wave your hand in the air. Swipe your thumb over its touch-control
surface. All your gestures and motions can be used to control other consumer
electronics. The $150 gesture-control ring is packed with an accelerometer,
gyroscope, compass and temperature sensor.  

Read the entire article at:
http://www.techhive.com/article/2148982/nod-is-a-gesture-control-ring-that-aims-to-make-your-finger-the-ultimate-input-device.html

Link:
Hellonod.com 
http://www.hellonod.com/

Related:
One ring to rule all the devices
http://sdt.bz/content/article.aspx?ArticleID=68858&page=1