A few days agao one of my colleagues asked if I knew of any websites containing data that would be useful for her teaching. Swivel seems to fit the bill.
The website creators, Dmitry Dimov and Brian Mulloysay say "Swivel is a place where curious people explore all kinds of data.... Swivel's mission is to make data useful so people share insights, make great decisions and improve lives".
This site provides access to a vast array of data sets on a wide range of topics which can be explored graphically. Data comes from both official and non-official sources. People can add their own data and make it public (for free) or keep it private (at a cost).