So yesterday I launched http://twittermusictrends.com/
. It listens for tweets mentioning a band or artist, collects statistics on it, and displays those in real-time.
It's highly dynamic, automatically updating several times a minute with tweets that come in. Although people enjoy the old-skool green-on-black terminal aesthetic (it was born of necessity—having been prototyped at a Music Hack Day in ~8 hours), I'm most proud of the architecture: it's served entirely from static files by nginx. The back end uses (my) Twitstream, Redis, and Celery (calling out to the Echo Nest's API) to generate over 200 of those static files every minute.
The site is also its own API: each page has a (slightly richer) JSON representation so that more talented/motivated GUI wizards and data junkies can show the same data their own way.