Google Maps
OH MY, this is so cool.
https://maps.google.com (via Julien Couvreur).
I don't get how they make money on this one yet.
Of course, I just created a SlickRun (the sweetest application launcher) shortcut for this:
magicword=map
filename=iexplore.exe
parameters=https://maps.google.com/maps?q=$W$
then type map sfo and you will get a map of the SFO airport.
For MSN Desktop Search that would be:
@map,https://maps.google.com/maps?q=$w