Here's one of my own, since the previous one was for someone else's story...
I use Google Earth
a lot for stories. Makes me wish Metropolis, Gotham, Star City and such could be found on there, in fact.
When I was writing Reversal of Fortune, I used it to map out a route that my character would be likely to take through the desert. I also spent over 10 hours reading about Egypt and and neighboring countries -- all this for about 3 or 4 chapters in the story. Worse thing is that this was ~10 hours of research during NaNoWriMo, when time is very limited. *lol* I wanted it to be realistic since this was supposed to have been written by someone who'd been there...
I used it when I was writing Blizzard, too - to figure out where the cabin might be, which towns they might pass on the way there and how long it would take them to get from point A to point B.
And I used it while I was writing my latest NaNo novel because I needed to figure out which countries the character would go through in order to reach Nepal.
