I installed many cool Firefox add-ons before, but I have never seen like this interesting add-on. YouPlayer simply lets you watch your favorite videos in Firefox sidebar. You may add/drag a video link in to the playlist and watch it or download it. After you download the YouPlayer you might notice that the playlist functions similar to Winamp media player. According to the add-on author, YouPlayer currently supports Google Video, MetaCafe, MySpace and YouTube. In addition, you can just drag a video from your local drive and play it while surfing the net.

What makes the add-on different is that you don’t have to stay on Toutube for example to watch the video, while browsing other site the video will be playing on the sidebar.

Instructions how to use it:

First download YouPlayer here, once installed go to View>>Sidebar>>YouPlayer.

Then the player will appear on your left side, go to Youtube for example and find a video you would like to watch, then drag the link to the playlist.