(written on 9-25-2010)
For posterity's sake, the first time I saw the International Space Station go overhead was on August 27, 2010. It was 8:30 in the evening and the sun was just starting to set, but it was still plenty light out. It went from the SW overhead to ENE and had a magnitude of a whopping -3.6. I saw pretty much the entire 6 minutes it was visible. It just kept going and going and going. I didn't wait for it to fade was as I did with the next ISS sighting. The international code for the ISS is 1998-067A.
Updated June 21 2011 to put the sightings in my standard template format
Here's the time-line of this evening:
Date: 27-Aug-2010 Friday
8:36 PM - Name: Internation Space Station aka ISS - Magnitude: -4.2
Int'l Designator: 1998-067-A