Chris W wrote:

I have been looking at some satellite photos on the web and I got to
thinking, I wonder if they have ever snapped a photo just as an airplane
was flying by. Has anyone ever seen that in a satellite photo? Some of
them are pretty detailed and you could easily make out the bigger planes.

Microsoft's TerraServer has satellite images of pretty much the entire
US. I don't have a specific link at my fingertips, but over the years,
various TerraServer links have been posted to newsgroups containing
images of larger airliners (either approaching or departing the airport,
never en route) and aircraft shadows near airports.

If you have some time, go here, then zoom into a few of the major
airports. You just might find a few:

http://terraserver.microsoft.com/

--
Peter