UT Clubs:

University Flying Club

Watching the sky:

Heaven's Above - Track Spacecraft / Stargazing
Download Seti @ home - Help SETI find aliens
Austin Astronomical Society
National Weather Service - current condition in Austin
 

Space News / Information:

Space News @ space.com
NASA (every space site has to have nasa.gov)
Launch Schedule
J-Track Satellite Tracking
 

Pilot and Aircraft Related sites: