As you may know, our browser OWB can't play YouTube video directly, due to (currently) missing support to both Flash and HTML5 formats, but the good news is that we can access to YouTube contents as well, using our traditional MacGyver-like ability to adapt available instruments to do something they weren't originally supposed to. This time, our saviors will be OWB (obvious), MPlayer and a wonderful little program called YouTube Clipmon, whose duty is basically monitoring the AROS clipboard, look for YouTube URLs and stream embedded videos to MPlayer. Normally, you should run YouTube Clipmonand and OWB independently, but Icaros Desktop has a proper script already made for you. You can find it using AmiStart following this path: start > my software > networking > web apps > YouTube. But you can also find it directly in the extras:networking/apps/web apps drawer.
Once the script will be launced, you'll spot YouTube Clipmon's little window appearing on the upper left corner of the screen, immediately followed by OWB, which will be opened straight to youtube.com.
Now interact with YouTube site as usual, looking for your favourite contents. When done, double click on the URL field of OWB and press rAROS+C to copy the address in the AROS clipboard. Immediately after, Clipmon will start streaming the YouTube video to MPlayer, which will be automatically launched a few seconds after. Enjoy your favourite videos!