Windows 7 Tip: 
From the creators of Download Accelerator Plus (DAP), pioneers of acceleration technology, now comes a new groundbreaking software! SpeedBit Video Accelerator for YouTube.com makes your videos stream faster and play smoother, reducing buffering problems and video “hiccups”.
When you watching a YouTube video, the YouTube interface will simply show multiple leaps a head of the video caching bar resulting in much faster completion of the caching/downloading of the streaming video, whenever a video is being accelerated a small message will show on the right bottom side of the screen indicating to the user that the acceleration is active.
I came to know about this by dap , dap provide additional facility of this software .