A smart little round box dubbed Knocki makes any surface sensitive to tapping or knocking. The Kickstarter campaign for Knocki has already pulled in over $700,000 in pledges, so it looks like a lot of people are interested in this capability.
 
Knocki is designed to be placed on a table or attached to a door in order to detect vibrations caused by tapping or knocking on the mounting surface. You can even teach the device to recognize commands – for example, knock once to switch on the TV, knock twice to turn down the sound or knock three times to turn it up. Knocki can send the commands to another device over a Wi-Fi link. Knocki could also be very handy for elderly persons who have trouble dealing with small buttons, or for alerting an emergency response service.
 
About 4,000 advance orders have already been placed for Knocki. Right now you can reserve a Knocki for $89 if you’re interested. It all sounds very nice, but we wonder whether the device will actually be used regularly once the initial enthusiasm wears off.