You won't realize how loud your mouse is until you hear the Nexus Silent Mouse. Actually, you don't hear it at all, which is the point: Nexus' new mouse is designed to eliminate the constant clicking sounds associated with mouse usage.
The Nexus Silent Mouse works the same as a regular mouse; it has five buttons and is powered by two AA batteries. You can't really see the difference in Nexus' new mouse until you hear it. The video here has a demonstration of the Silent Mouse quietly clicking away.
As anyone who works in an office with close quarters will tell you, silence is often the most deafening sound. Even when the music is off and the conversations have ceased, you still hear the incessant clicks of mouses and keyboards. Could a silent keyboard be next for Nexus?