Niels H. Christensen on Semantic Web Recipes presents how to load and parse linked-data and render in conjunction with Google Charts. He consumes a sample government API that supplies bus transportation data. This walkthrough formatted how-to is fit with code examples to aid the reader.
Is there any question map mashups have gone serious? How about billions of dollars serious? The U.S. website Recovery.gov was built to make transparent the use of economic stimulus money. Now you can track every dollar on a map.
The internet is the perfect medium for matching supply with demand. You can find your next freelance job or, as Craigslist has been singled out for, find just about anything else (if you know the right euphemisms). Now, with Data Marketplace, you can request or provide datasets covering anything you can think of.
There's still government hoops to jump through, but the US Census is making much of its recent data available by the slice, rather than the whole pie. The US Census Bureau API provides access to 2010 Census data, including demographics, income and how many women in New York take public transportation to work (and that's excluding taxi cabs).