Video Test -- new and improved

The new experiment that I mentioned recently had a persistent bug. I finally managed to track it down yesterday and fix it. So my apologies to anybody who wasn't able to complete the experiment due to the bug (feel free to email me to ask about how it would have ended and what it was about). For those of you who haven't taken it yet, I think this is one of the most enjoyable experiments in the bunch, so I highly recommend it to everybody.