TwitCam (http://www.twitcam.com) is a new free service that allows you to stream live video to your Twitter followers. You must have a Twitter account to use TwitCam.
TwitCam posts a video description and link for your Twitter followers to find your video. When you are broadcasting from your camera, you can chat with your Twitter followers directly from the broadcast page. You can also record an archive of the broadcast.
Although this is intended for live broadcast to an audience, it could also be used to create a promotional or informational video that you want others to view asynchronously.
At the moment the service has a lot of test videos as examples. It will be interesting to see the videos that are created as the service grows!