I am looking to do something similar in Medialab (response time is NOT an issue, although an IRT may be in the offing). I note that you are not using HTML for this particular stunt (I can't view it right now--need to install DirectRT first....doh!), but can something similar be done in medialab without HTML?

I want to present 4 videos on screen and allow the person to select one of them as their response to the question. Is this a possibility? Or is only going to work if you have HTML?