Perhaps I'm coming to the party late and you've already known this, but I didn't realize Google Adwords was working with Google Maps. I have a site that I've been experimenting with. In the background, I have a database that resolves your IP address (your network address) to a latitude and longitude. I then use that latitude and longitude to display the center of the map.
I haven't touched the project in a couple months and just began working on it once again and here's what I found:
There are NO, I repeat NO, mentions of the geographic location in the application since it's International so Google must be serving up the advertisements off of the map location.
Pretty slick! They must be utilizing the centering latitude and longitude (or the tiles of map images) to determine the Adsense Advertisements. I am absolutely 100% impressed (and I need to get this site up very soon!). You Google guys (and gals) are some smart dudes (and dudettes).