Although the service is still very much in its infancy and has been down at times. For now it only has few Live channels and about 500 online viewers, something that is expected to rapidly increase in a few days time when it becomes popular. It has a user friendly interface and I think it is worth to give it a try. The service combines many of the best practices developed by early explorers of the medium, tiny startups.
Using Yahoo Live as many as five participants can do video and audio on one page together, it also has a chat option which gives users choice over fonts and colors and express themselves.
Yahoo Live also has put up an API where users can use the service and get content out on other places. The Yahoo Developer Blog talks more about the API. Following as some of the API features:
* Find out who's broadcasting right now
* Get data about past broadcasts
* See snapshots of past broadcasts
* Embed live video in your blog or web page
You can also have a look at the API Docs and there is an example of how you can use it.
Here is also the official Yahoo Live Video