• Download SpeedBit Video Accelerator which makes videos from YouTube and many other video sites faster by reducing buffering problems.
• The URL Hacking: Add a simple &fmt=18# to the end of the normal YouTube video URL would make the hi res video, if it exists, to load On the other hand if you would like youtube videos which are of better quality then remove the # from the end.
• Search faster and Watch fast youtube videos with Youtube Search.
• Use an Firefox Addon which is really cool - YouPlayer (If you not using FireFox please excuse me.)
• Change the Youtube Video setting to better suite you.

Off course if you find any new ways please take time to add as comment.