Nice video on cross counter about how to do it.
The only real difference between how I do it and the mehtod described are:
1) I use a PVR instead of a video card for the sake of portability.
2) Instead of splitting via HDMI I split via component which means I can feed the sound signal through my mixing desk which gives me physical control over all the volume levels in one step (if you use HDMI, you have 2 seperate sound signals which is a little more work IMO to manage). Still, I am considering upgrading the PVR to a HDMI device as 1 cable > 5.
Thoguht it might be good to have a techy/recordy streamy thread anyways.