Have you noticed the points of interest data that is now incorporated into Google Maps when you zoom in?
I know it has been there for a while but I only recently discovered that it is clickable – could be I just missed it or it could be because the click tolerances for some of the tiny square dot icons are very small or it could be that it is one of those neat tiny changes that google just slips in from time to time (well almost every week actually). No doubt Ed Parsons if he is reading this will chip in and tell us when this feature launched.
In addition to restaurants, hotels and cinemas I found Muswell Hill railway station. Hah I thought caught you out Google! There is no Muswell Hill railway station, the line closed ages and ages ago. But when I found the click zone on the item up pops this useful bit of local history from wikipedia
Now you can see how Google will start to drive revenue from all those sites using the API to embed maps or develop applications, the adverts will be embedded in the map. Now can they make them context and user dependent?