Here's a site that has a late 1980s look and feel, but it does the job:

http://spaceflight.nasa.gov/realdata/sightings/ci...

It's a little hard to figure out at first, but once you have the hang of it, well, if you are like me you check it all the time, hoping for a good sighting opportunity. There aren't as many in the summer (I'm not getting up at 4 to watch the space station!) but Monday July 6 I'll be outside at 10:13 watching it zoom across the sky.