Become a YouTube expert

Watching videos on YouTube seems pretty straightforward, but if you want to enhance the viewing experience there are some official, and unofficial, tools that can tweak the presentation.

Setting YouTube to automatically play the high-quality version
You have to be logged in to make this work. Simply go to YouTube's playback settings and pick the 'I have a fast connection' option. The next time you play a video it will automatically switch over to the higher-quality stream. Worth noting is that this doesn't yet work for HD videos -- you still need to click on the HD button to make it switch over to that stream.

Make HD videos fit the screen better
Viewing a video in HD resizes from the standard 710-pixel player into one that's 950 pixels wide. It still doesn't go to the edges of the page though. To get that extra 100 pixels or so you can install this small Firefox add-on, which resizes them to fit the rest of the YouTube UI. Of course, you could always just hit the full-screen button, but this lets you access all the other page elements while it's playing.

Turn down the lights on any YouTube video
A select few YouTube videos have the option to "turn down the lights", which darkens the rest of YouTube's UI and shows you just the video. If you want to make this option available on all videos you can download YouTube Cinema for Firefox, which can do this for you automatically. It also lets you change the background colour.

See also Quietube and Theeter, which do the same thing using a special bookmarklet you can add to your browser. Unlike the Firefox extension, however, both of these services require using the bookmarklet to turn it on when you're browsing videos on YouTube proper.