Here is the Houston sightings link:
http://spaceflight1.nasa.gov/realdata/sightings/cities/view.cgi?country=United_States®ion=Texas&city=Houston
Here is the generic sightings search link:
http://spaceflight.nasa.gov/realdata/sightings/index.html
Here is a real-time world map showing current positions and the next few orbits:
http://spaceflight.nasa.gov/realdata/tracking/index.html
Thank you.
NASA TV link
I happen to like this one:
http://www.heavens-above.com/