For larger movies I was think of plugging DV camcorder to my G5 (through a DVI-Video adapter). But I have no clue if that will work.
Or what if I hook up a TV as a second screen, and attach a camcorder to the video out of a camcorder? Is that possible? Can you record stuff from your TV with a camcorder? (I haven't one around to test)
Hey Dutch there are some camcorders that have video input (expl : Sony DCR-TRV950E)
As for hooking up a tv-monitor and recording from that TV, you will need a TV monitor that has a video out feature so you can make a link-through (doorlinken)