Is there any way to cost efficetively record Xbox 360 gameplay in HD?

I have looked around for many methods of doing this, dazzle's, capture cards, HD PVR's, and other various methods. i heard around the web that someone figured out how to actually hook up an ethernet cord from a pc to a console and they managed to use it to record HD gameplay...i am skeptical about that perticular method, but if it works please let me know. i want to become a reviewer/ general game channel on youtube, but in order to do that i need a way of getting HD gameplay. so if there are any cheap( or possibly free) methods of recording gameplay, please share with me so i can launch my reviews.