The Tracker will display the location of the space station along with 
the current altitude and speed.  It also displays it's past, current, and future track
around the earth.  This is helpful if you want to try for a visual siting. 
The tracker also displays the position of the sun along with night and day shading.

There are many other NASA links that you can visit from the tracker page. 

Click Here to visit the Tracker Site