So, it's time to admit that my "half dome", G4 700 isn't cutting it, in this age of You Tube and other huge downloads. I'm getting the "stop and start" thing, most of the time, when I try to play a short video. I've got what I'm told is the maximum RAM, 512 MB, and, of course, the stock 700 MHz processor. The question is, can my computer be upgraded? I've been told that the answer is no, but I thought I'd check with the best minds (that's you) before I scrap it and go to a 21st century machine. Appreciate any advice you can give me, and thanks.