...My Internet is going soooooo much faster...Guys, try it. Its absolutely astounding.
This is, if you haven't noticed yet,
MacRumors. Also if you haven't noticed, Google Web Accelerator is Windows only.
Also, it's not faster, it appears to be faster because google is doing things like prefetching pages and caching them on google servers to make it appear faster (since they have so many all over the place). It's only going to benefit you if the site in question is overloaded or very slow.
Lastly, it should have no effect on youtube because the biggest bandwidth usage on a youtube page is streaming video, which is not cached or prefetched by web accelerator (although, google did acquire youtube). Any perceived performance increase on your part does not actually exist.