Formative Assessment Tool

As my class has been working through the roles of a literature circle, I wonder if Voicethread could be used in place of the typical worksheets that individuals fill out to carry on a group discussion and show their comprehension?  I could see using Voicethread as a tool to have students share their thoughts on a certain role by setting up slides and having the students comment their thoughts on their role and have other students comment back on the original comments.  This could be a nice way to "hear" all the group discussions without being there.  I don't think it would be something I would do all the time, but it could be an interesting way to spice things up and have more "contact time" with the students, even though it may be at a later time.  Then, individuals could be pulled as needed for extra instruction.