[hga]

If this is a serious question I've got ideas, and I strongly recommend reading a particular slow glass story by Bob Shaw (http://en.wikipedia.org/wiki/Slow_light#Slow_light_in_fictio...). This last one I remember, as he worked through the possibilities, entails the authorities spreading very small spheres of slow glass in public places. If an incident occurred, they'd just vacuum up some of them and wait for the light to get through and see what happened.

Which brings me to my first point: passive always on is nice, unless of course you are the criminal, but expensive in battery power for which there is no Moore's law. Given that, it should take very little to get it going, which isn't necessarily compatible with the MVP of a smartphone app capturing sound.

[DanBC]

How expensive is a rolling buffer of 1 minute, which then gets written to disk (with everything following it written to disc too) when a button is pushed?

I'm imagining something like the Cisco Flip but at 360 (or maybe 720) and with much better batteries. (My Flip uses 2 AA batteries or a rechargeable battery pack.)