The utility that would be useful here would be something like a "virtual audio cable" that takes the input from stdout and redirects it to a new device that *can* be recorded to. (Posted by roger pack)
This linux kernel module: http://gitorious.org/tw68 - adds video support for the Techwell 68xx based chips like the 6805A, but not audio support. (Posted by Roman Gaufman)
The video lan tools can be used to create a canvas with multiple video and audio sources, this is the "vlm" feature. We are pulling two video and one audio source, the video are in perfect sync the audio however is not, all sources are from the same type of equipment and properly timestamped. There is a bug in vlc when syncing more then 2 sources. (Posted by Keith Page)