The first site is offered by the educational Web site BrainPOP called Humidity Movie (1), is part of the humidity measurement manufacture Rotronics larger Web site. Several subjects are presented including the Physics of Humidity, Humidity Definitions, and the Effects of Temperature and Pressure on Humidity. The third site on humidity is presented by USA Today's Weather Web site called Humidity Formulas (3 ). Visitors will find information on the heat Index and apparent temperature, learn how altitude affects humidity calculations, how to get the relative humidity from temperature and dew point, and even link to a humidity definitions page. The fourth site from wunderground.com offers a national humidity map called US Humidity (4). Besides the map, users can click on a specific state to view local humidity and other weather-related conditions. Next, from a New York city school teacher comes the science lesson plan Web site called How Can We Make a Simple Device to Check for Humidity in the Air? (5). Prepared for grades K-8, the simple lesson allows students to make a device for checking the humidity using cobalt chloride strips. The sixth site (6) is offered by the CSGNetwork and Computer Support Group Service. The calculator determines the relative torque and horsepower available at any temperature, barometric pressure, humidity, and altitude after the users inputs all the necessary information.