We have two Canon VIXIA HV30 cameras. One is trained on the white board and is recording in HD (one frame a second). The other is trained on the prof and is recording in SD. Both of these feed into the recording computer via firewire. We have two mics that are mixed and then fed into the computer. One is a lapel mic on the prof and one is a ceiling mic for recording classroom interaction. The ceiling mic is nice b/c it serves as a backup should the lapel mic fail. It does bring down the audio quality tho. It's a tradeoff; the more we try to pick up classroom interaction, the less audio quality we get. Using just the lapel mic gives pristine audio quality but no capture of student questions/comments/etc.