Ustream (www.ustream.tv) is a website that allows users to stream live video content straight to the internet. Video content is recorded via a webcamera or video-enabled smartphone. As the video records, it is simultaneously streamed to the user's channel on the ustream website. Non-users can view the live stream on the ustream website, while users can also participate in chat rooms on the site.

Users on Ustream and similar sites such as livestream and justin.tv often use the websites to constantly stream their daily lives, i.e. "lifecast". One of the better-known livecasts is that of a family of Shiba Inus: http://www.ustream.tv/sfshiba

The free version of Ustream is ad supported, so ads may sporadically pop up in the video player or to the side. Premium Membership is only $3.99 a month, removes the ads, and allows for more customization options, as well as perceived credibility. Pro Membership allows for even more customization, but starts at a steep $99/month.

A supplementary program made my Ustream called Ustream Producer allows for editing on the fly; being able to splice videos and images directly from your computer and into your live stream. The basic version is free, with premium versions starting at $199 and allowing for HD broadcasting, multiple cameras, and other features.

Pros

• Video is live (more or less)
• Free/cheap platform
• Easy to use - just create an account and start filming, and the video will stream!
• Chatbox, social stream, and polls allow for interaction with viewers 
• Great for live sports, political events, music concerts, Glee commercial break commentary
• Past streams can be archived

Cons

• Video is live (more or less), warts-and-all (no post-editing)
• Slight lag time exists between recorded video and stream; noticeable with smartphone video 
• Free model has a number of limitations (ads may interrupt live video, limited to single-camera shooting)