One excellent example is of British Columbia's budget update by blprnt:
BC Budget Visualization Tool from blprnt on Vimeo.
blpnt seems to have quite a talent for visualisation, below is his work regarding people saying good morning on twitter:
GoodMorning! First Render from blprnt on Vimeo.
The movie details approximately 11,000 tweets collected over a 24 hour period between August 20th and 21st. The tweets were harvested to find people saying 'good morning' in English as well as several other languages. It was built in Processing (processing.org) using Twitter4J, and a home-brewed client for MetaCarta's geo-parsing APIs.
It is well worth a visit to the blog - blog.blprnt.com, excellent stuff...