Aaron and I were just talking about this from BarCamp a couple weeks ago. There was one session which was a "realtime Ruby on Rails development demo" where the crowd would give a task and the coder would make it happen in Ruby on Rails (with his workspace on the projector) while we all ate lunch. Interesting idea.

The coolest part wasn't just that the guy did the task (he did; Ruby is cool), but that there were two other kids off on the side who sort of announced as the end of lunch drew near, "hey are you done yet? Team JavaScript is almost ready."

JavaScript, for non-nerds, is the redheaded stepchild of web-programming languages. But they made it happen in the same time as the Ruby on Rails (the flashy new thing) developer did. Granted these guys were serious JavaScripters, but nevertheless, it was a great moment.