Hey wbnet!
So ya, I use this plugin.
When you want to insert a video in the sidebar type this in the tag field (in the widgets).
[flashvideo file=https://yoursitename.com/yourvideofoldername/moviename.mov /]
Keep in mind, you need to set the video size in settings, under flash videos.
Good luck!
p.s.
I don’t think you use this plugin to show youtube videos on your site. I’m not sure, maybe you can, but my impression is that you use this plug in to display videos on your own server. I would recommend another plugin called “simple Youtube” if you want to show youtube vids on your sidebar. I only use this to play videos on my website that I uploaded on my own site.