One thing we see a lot of in healthcare is Powerpoint presentations. I recently captured a conference that had 5 speakers presenting from Powerpoint. We had one computer with Powerpoint and
Camtasia Studio loaded on it, and a wireless clicker. I sat at the presentation computer (a laptop) and loaded the presentations from USB drives, clicked the Camtasia "Record" button (it has a Powerpoint plugin), then hit the start presentation, and the rest was up to the presenter. There was a sound system in the auditorium that I could have run to the microphone input on my computer, but I ran a second microphone, which was an inexpensive Audio Technica that I bought a few years ago from a local electronics store.
After each presentation, you quit Powerpoint as usual, and Camtasia asks you to save the file. You can then immediately compress the file in your preferred format, or you can go back to the project later in Camtasia and work on it.
We have found that using the IPhone high resolution compression works the best if you are going to upload the file to Ning. Ning may tell you it can't recognize the format, but it always uploads in our experience.
Here are some shots of Camtasia in Powerpoint...

