There aren't many, but one of the downsides of the digital revolution is noise pollution. The proliferation of gadgetry in our society has given rise to a constant cacophony of beeps, rings, buzzes and Beyonce ringtones. On any given day, the sound of our own phones is enough to push us over the brink, which is why we usually keep them on vibrate. But even a vibrating phone can sound like a buzz saw when it's bouncing around on a wooden desktop.
Here's one possible solution that could work equally well in a deafening office where a phone can't be heard above the din or a private study where silence is always golden: The "Signal Cell Phone Adviser" is a handset cradle that flashes a non-auditory light to indicate an incoming call. It's not entirely clear how it works, but we really don't care as long as it stays quiet and does its job. Which, as we all know, is a rare commodity these days, human or non-human.