Screencast is a portal where you can post videos, tutorials and slide shows for students, parents or peers. It has a much more professional polished look than Youtube. This is what it looks like with a video playing:
You can organize your content in folders and determine who will see the content with sharing permissions. You can embed the content into another web site or email the link. You can send specific invitations to people and give them permission to see the content. Or you can keep the content public and share the link with your class. Each folder can have various permissions attached to it. This is a free service with upgrades available for a price.