Here's a video I shot at Maker Faire UK 2011. I took the Turing machine along having just rebuilt it without testing, but it worked fine over the weekend after a little prodding and adjustment. I don't think everybody understood it, but everyone was positive about it and those that did understand what it did seemed very amused by it.
I didn't get much chance to have a look around the rest of Maker Faire, but it was an excellent event with some great minds getting together to create some great hacks (a video of Kinect controlled Tesla coils is doing the rounds at the moment).
Now that deadline's over, I can go back to the drawing board and start thinking about how to make a more reliable, precise version of this machine, or a more powerful machine which could actually demonstrate something useful - which would be better than explaining that this Turing machine would take months to add two numbers together.