TubeTV is a freeware program for Mac OS X which enables you to search for, save, and convert YouTube and other flash videos to a format suitable for playback on your favorite devices.
CoveritLive's web based software publishes your commentary in real time like an instant message. One-click publishing lets you add polls, videos, pictures and audio clips instantly, and take questions.
Screencast-O-Matic is a new web-based screencast program that is incredibly easy to use. And since it uses a Java applet, it runs on Windows, Mac, and Linux machines.