Here's a very simple YouTube feature that's really useful. YouTube started to add a "play" Unicode character to the title of the YouTube page, but only when the video is playing. Pause the video and the "play" character disappears. It's a great way to find a "noisy" tab, especially if you open more than one YouTube video.
The "play" symbol is actually
the black right-pointing triangle Unicode character. It's small, subtle and it's better than an animated favicon.
Here's an example: there are 2 YouTube tabs in the screenshot below. In the first tab there's a paused video, while in the second tab there's a video that's playing.
