Researchers at Carnegie Mellon University and Intel Labs have developed a system of "whack gestures" that could allow any phone with an accelerometer to be silenced with a punch. This is brilliant.

Tap gestures as a concept aren't totally new, but the new software promises a much lower error rate than previous solutions, as well as a much simpler philosophy. Chris Harrison, developer:

I think for whack gestures to be commercially viable only two gestures might be desired: one to silence the phone, and a second to postpone an alert, ask the caller to try again in 5 minutes or snooze an alarm.

The potential here, in you haven't noticed, is huge. Imagine the time you'll save, with this shortened call-killing routine! Not to mention the instant, visceral gratification. It would take this process:

1.) Receive call during funeral
2.) Panic, violently strike outer thigh
3.) Calm down, internalize shame
4.) Remove phone from pocket, interrupting somber moment further
5.) Switch off phone in conspicuous way, as if to apologize
6.) Sit through the shutdown jingle you totally forgot about, because who switches off their phones anymore?
7.) Continue mourning, now tinged with embarrassment

and condense it into this process:

1.) Receive call during funeral
2.) Don't panic, violently strike outer thigh.

Perfect. The project is still in research and presentation stages for the time being, though any company run by people who've owned a cellphone, ever, will license this technology. Obviously. [New Scientist]