The author of gCensus, Imran Haque, is a PhD student in Computer Science at Stanford University. He contacted me back in late February that he had released a subset of three states of many kinds of visualization using US Census data and Google Earth. But, he only had space for three states (California, Pennsylvania, and Oregon) since the dataset is so large. You can visit his web site for background information and try the application here (it starts with you selecting the data through a web interface). Once you select the location and information you want, his application builds a Google Earth file that lets you visualize the data in an informative way inside Google Earth. This is GIS visualization without having to buy GIS software. There is a large amount of data in the census database. This is a valuable resource for those wanting to understand things based on the census data.
I waited to write a story about his collection hoping he would soon get more states up. Well, in the meantime he apparently won a contest with ExtremeTech who gave him a huge boost in publicity. You can read an article they asked him to write which gives more information about the project. He subsequently got Slashdotted and Dugg. Imran has now received a donation of more hard drive space so he can host more states. Hopefully he will soon have more states available with gCensus. I guess I missed out on a big scoop. Great work Imran!
See another example of census data visualization in Google Earth.