Sidebar for YouTube (Firefox and Opera) allows you to access the mobile version of YouTube displayed as a functioning sidebar.
A nice little add-on that will allow you to utilize YouTube as you browse elsewhere. Great for watching MajorGeeks tutorials and video guides, for instance. Even though it is small, you can still follow along, and if you need a larger version, you can easily pop out the video and view it normally while keeping your browser content open in another tab. The only downside with the pop-out is that it starts the video at the beginning and not at the current view time.
Sidebar for YouTube Features:
Easy one-click access to YouTube via browser sidebar
Supports all YouTube functions in mobile view
Listen to your favorite music or watch video while browsing the web