digg.com/spy ajaxy shows in real time every action happening on Digg: a user submitting a new story, a user voting for or against a story or commenting on it. Pretty impressive ongoing picture of a lively community (below iframed for your convenience, shoot an eye while reading the rest).
I use this web page fullscreen before my presentations about anything2.0 (you know, the “let’s wait few more minutes” period in which the organizers hope 5 additional people’ll show up somehow doubling your audience). I think it unconsciusly introduce many of the memes that will percolate through the presentation (user participation, wisdom of the crowds, …)
I kinda remember someone called digg.com/spy “democracy in action”, I would not disturb a concept such as democracy for this but surely it is a rare example of transparency which surely contributes to making the system less of a black box.