I have used many of the Inventor sample files for years to test Inventor functionality and to show others examples of Inventor use. In Inventor 2011, these samples are no longer included with the default installation. Autodesk has opted to post them in a location to download where they can be updated. You can now download the samples from: http:\\www.autodesk.com\inventor-samples
The Blower assembly is particularly good at showing the new Inventor 2011 visual styles.