Texas Earth & Space Science Revolution 

Global Positioning Systems:
UNAVCO Education and Outreach - learn how GPS works and how scientists apply         data to plate tectonics.


Satellite Imagery:
NOAA Satellite and Information Service - high resolution, detailed imagery of significant envornmental events which are visible in remotely-sensed data available at the NOAA Science Center in Suitland, Maryland.

NASA MODIS - views the entire earth surface every two days. Great images of the atmosphere, land, and oceans.

NASA Earth Observatory - You've got to visit this site!