Screencasting
Screencasting is a cheap way -- read: free -- to produce quick videos.
Capture anything on your computer screen. Narrate it. Post it on YouTube.This guy did it. He used a free version of Screencast-O-Matic to produce a video on President Obama. It has had 500,000 hits.
You can see the Screencast-O-Matic watermark in the lower left-hand corner. If you pay $15 a year, the program does not put this on your videos.
That's how I know he used the free version.
The video is pretty funny. It's a political video. It explores an odd statistical correlation. When the President speaks, people faint. This affliction is now spreading. Hillary Clinton is now afflicted. Watch the entire video.
The entire faculty of the Ron Paul Curriculum uses screencasting to teach.
You can see examples for each course.
Use a $30 microphone, such as a Sennheiser unit.