Have you considered uploading the powerpoint to Voicethread and letting students record directly into voicethread for their responses. I'm fairly certain it can be set so that all comments are moderated so the students wouldn't hear each others responses until the instructor released them. Or they can be released immediately. I'm not sure what the scope of the exercise is to know if matters that students hear each other immediately.
At the very least, this would keep from the instructor starting completely over with something new since what she has can be uploaded.
Lauren Rosen
Collaborative Language Program
University of Wisconsin
618 Van Hise Hall
1220 Linden Drive
Madison, WI 53706
[log in to unmask]608-262-4066 (voice)
608-265-3892 (fax)
http://www.uwosh.edu/programs/clp/