Monitor conversations and save the last xx minutes/second

[niklasa_uk]

Hi,

You know those camera apps you can get to use in your car that records on a loop and if something happens like a crash, it saves the last half minute or so?

All I want is an audio app that does the same thing, that I can start running on my phone, and when someone comes out with a good joke, or a bit of info I want to keep, I can just press a button or tap the screen and save the last part of the conversation. I've tried searching but nothing seems to do it. It obviously can be done, from the plethora of apps to record video, GPS, speed etc in cars.

Does anyone know of an app that will do this, or willing to knock something up for me?

Thanks in advance.