YouTube Video Speed History -- check your video streaming speed!
OK, by now now you've all clicked it. The silence is deafening. This is definitely one of those 'ooh, cool... but... er... so?' things. Well I say that, but I know there's a whole bunch of computer enthusiasts out there that simply love to compare their performance against other people. YouTube says that it collects connection info to finely tune your video-watching experience, but it's nice of them to make the data publicly visible!
I'm afraid I don't really have anything else to add. You can't view the statistics for people in other countries, nor can you manipulate the data in any other way. That's it.