I haven't actually done this method but I think it would be the best, unless the game supports in-game recording, then that would be the best method. Hook your TV out on your video card to a camcorder, and record the video. Then connect the camcorder to your firewire port and import the video.
If you have a P4c proc you could assign fraps to one of the virtual processors and the game to the other. Doubt that would help much though.