Skimo TV extension lets you skim the video in an YouTube Page
While watching any of the YouTube videos from approved users, hit the skimo tv extension to skim the video.
Try Robert Scoble's channel for example.
Start with
http://www.youtube.com/watch?v=NNbOFfa8kKI&feature=c4-overview&list=UUQCV_2mN0iHzwGRFjbsszBw
and try pressing the skimo tv extension