I've been wondering if theres a bit of software out there that would enable me to use my Webcam like a PVR device.

I want to set up my webcam as a DashCam, but wanted the functionality of where its continually recording in the background.

I'm looking for something that will continually record the last 10-20 mins in the background, and then if i wanted to save an event (ie i witness an accident) i can hit the save button and it will save the 10 mins before i hit the button, rather than miss the lead up.

any ideas?