Last night, I got a excellent view of the space shuttle just after it undocked from the space station.
It was really cool, seeing the shuttle flying just a little ahead of the station and slowly pulling away, as it moved to a different orbit in preparation for landing.
The undocking occured at 7:53 local time and they came into view at 8:12.
If you want to see them, you have to be looking at the right time, as the station is only visible in the evening, just after sunset.
It appears like a plane flying high overhead, for about four minutes.
There should be another opportunity to see them in the same sky, if the sky is clear, before the shuttle lands.
Check the human space flight sightings page for times for your area.
Human Space Flight (HSF) - Realtime Data