National High Magnetic Field Laboratory
Magnet Academy: How Atmospheric Pressure Affects Objects
A bell jar, Peeps and balloons demonstrate how changing the atmospheric pressure around objects can change their size. [3:18]
Science Museum of Minnesota
Science Museum of Minnesota: Air Cluster
Interesting site with links to activities about wind and air in many forms. Browse the different activities and investigations on the properties of air on the toolbar to the left of the page.