OIT has services that allow you to stream live or pre-recorded videos to password-protected groups or to the world.
Wowza allows you to stream live to desktop and mobile devices to broad, non-password-protected audiences
Warpwire allows you to stream pre-recorded videos to password-protected or non-password-protected audiences as well as embed video in such applications as Sakai, WordPress, or the Duke Wiki
YouTube allows you to stream pre-recorded videos to non-password-protected audiences and is best for marketing or material that is meant to be consumed by a large, public audience
Apple Podcasts allows you to publish your content to Apple Podcast users on iOS devices and AppleTVs (note, we do not curate the site).