From the "about" page:
How do the States Compare? Mash up some government data to find out!
The Federal Government produces an immeasurable amount of data each day. DataMasher helps citizens have a little fun with those data by creating mashups to visualize them in different ways and see how states compare on important issues. Users can combine different data sets in interesting ways and create their own custom rankings of the states. Want to learn more? Watch this brief screencast.