I recently saw this post from the neowin forums so i decided to try it out. It says that for most videos that are on youtube, you just add a &fmt=18 at the back of the link and you will get a higher quality video of it instead of a default blurry version.
For those of you who are lazy to continously add the &fmt=18 to the back of each video, you can install a user generated javascript on your browser so it will automatically convert it to use the higher quality version of the video in youtube. The link to get it from is http://userscripts.org/scripts/show/31764
It works on Opera and Firefox with Greasemonkey Extension. Try it and you will find yourself watching better quality videos on youtube!
