The elections in France have turned out to be the one where neogeography mash-ups are used. Nicolas Sarkozy's website features mash-ups which showcase where expatriates can vote outside of France and the various places Sarkozy has campaigned. Ségolène Royal's website has a mash-up locating pro-Royal rallies in France. Even François Bayrou, who finished in third-place, has a mash-up showing local leaders of his campaign. Although one has to zoom in a bit to see any of the pins.
An interesting thing to note is that all the mash-ups are based on Google Maps. No one bothered with a competitor. The official French alternative to Google Earth, Geoportail, was not used because of the lack of API support for third-parties and other limitations.
Catholicgauze was interested to see how many American presidential candidates have adopted map mash-ups on their websites. The total count was zero for confirmed candidates. Only Wesley Clark's WesPAC had mash-ups. The website had a Frappr Map locating Clark supporters and another mash-up of WesPAC supporters. Personally, I think Coming Anarchy's Frapr Map has more registered users. So that's the said state of the relationship between neogeography and US Presidential candidates. Catholicgauze is hereby hoping for the day when a candidate releases a Google Earth KML file of their campaign, that would be cool.