ConvertTube is an online flash video converter.
This service allows you convert an Online Video like ‘YouTube videos’ to more popular formats like wmv, mov, mp4, mp3, 3gp etc. converttube.com converts FLV to the selected format faster and less lossy than a typical transcoder.

You never have to worry if the video is gone or if the internet is down.  You can save the videos in wmv format, edit them in movie maker, or insert them into a PowerPoint.