When we read the announcement that higher quality videos would come to Youtube we were delighted that the video quality would finally see an upgrade. Apparently the conversion has started and some videos are already available in different quality versions. It still looks like Youtube is testing settings and stuff and that not everyone can access those higher quality videos yet.
You can also bet that it takes some time to convert the 140+ million videos hosted on the website. The default video resolution is 320×200 and the two new resolutions that are tested are 448×336 and 480×360. To test it you only need to append the parameters &fmt6 for 448×336 or &fmt18 for 480×360 video resolutions.
Not all videos are converted as of yet and videos that have not are displaying the loading screen all the time.
320×200 quality: [link]

480×360 quality: [link]

Firefox users can access a Greasemonkey script that changes the video resolution. [via Googlesystem]
Related posts:
- Force High Or Low Quality On Youtube Automatically
- Youtube High Quality Playback
- Download Youtube Videos as Mp4
- Youtube To Add 1080p HD Videos
- See Who’s Watching Your Videos on YouTube
- Lyrics for Youtube Videos
- Watch Restricted Youtube Videos in any Country
- Automatically Buffer Youtube Videos

A better site for high quality videos is:
http://www.veoh.com
YouTube sucks, always has, so for those who want high quality now for viewing, uploading and downloading it’s VEOH. ;)