igniteCAST is a free service that allows you to create, upload, view and share video clips, interactive presentations, PowerPoint, quizzes, surveys and much more. You can easily and quickly create and broadcast media so that others can use and view it. It can even be used to create an online course.
You can share your media resources publicly or create a private channel. It's also a great resource to use for finding materials yourself. You can search the public feed for materials that others have shared to use in your classroom, or to have students view. You could also have students use igniteCAST to create their own projects as a great classroom project and assessment.
It's really a great service, allowing you to even add a table of contents to your presentation.
Here's an example cast: http://www.ignitecast.com/p/sRawWvZPkY/Ignite-4-Standard-Quick-Start-Guide