The other great use is for student programs. Those student programs can be put online, either video or audio, for relatives to see across the country. Last week I listened to a 2nd grade class that did a radio show using UStream.
I could also see you using this for staff development. Staff could watch and interact from the comfort of their own building.
A new feature just released is the ability to upload your saved video to YouTube, allowing you to then embed them on your own website. It's also handy if you are using YouTube for any other video in your district.
The bottom of the page also gives you some networking options, including Twitter, Facebook, etc.