Apple forced Google’s hand when it came to video, and now YouTube supports HTML5 video in addition to Flash. If you’re as sick as I am of Flash crashing your browser, eating up resources, and flooding you with ads, you probably added a Flash blocker plugin.
Rather than adding YouTube to the blocker whitelist or allowing each video individually, a new option is now available: You can opt-in to an HTML5 beta with desktop browsers, allowing you to view most YouTube videos without Flash at all!
It’s simple! Just go to http://www.youtube.com/html5 and click the link at the bottom to join the HTML5 beta test. This works with Chrome/Chrome Frame and Safari 4. Videos with ads won’t work, apparently, and some other videos appear to not yet be available.
Vimeo also has an HTML5 version, and it’s easier to get to. Just click “Switch to HTML5 player” below any video on the site. Simple!