So I have discovered how to stream (yes, I said stream) 720p youtube on an ibook G4, 1.2 ghz, 1.2 GB of RAM, 32 MB VRAM. Apologies in advance if someone else has already done this and posted. First, grab Tenfourfox 6 or beta of 7. Then install Flashblock and Flashvideoreplacer extensions. Installing flashblock is critical as it blocks other flash from running in the background and chewing up CPU cycles. You will need ALL of your lowly G4's 1.2Ghz for this to work. You also need CorePlayer. Its 20 bucks, but if you have a PPC mac you owe it to yourself to download it and fork over the moola. Flashvideoreplacer tries to replace flash on youtube and some other sites with quicktime. On Linux it works great, but on the mac it's uber buggy, works sometimes and not others, embedded doesn't work at all now, window mode does but only in low resolution so its not a good solution, but we won't be using it as is, but you do need it. There will be a small button at the far right of the address bar, where you can select preferences, and critically, copy URL. In Flashvideoreplacer preferences select "use mp4 over FLV", and select "high". This makes 720p streams visible. Find a 720p stream. I used this one: http://www.youtube.com/watch?v=HEheh1BH34Q In the flashvideoreplacer preferences select copy url to clipboard, then open CorePlayer, and paste that URL into it, command U brings up the copy URL window. Hit return and be amazed. On my ibook there is a teeny weeny bit of lag but its not THAT bad. And I confirmed it was truly 720p that was streaming. WOW. Now if someone would automate this whole process we'd be set. For a bit.