MusicianMix.com + Google Maps - Musicianmix.com uses Google Maps to search for music teachers, Bands to join or Musicians to jam with. (Registration required)
Zoomr.com + Google Maps - Zoomr has all the web 2.0 bells and whistles - large font, RSS for specific tags, TAGS! - and of course the "R" ending in the name. :) Photos that are tagged to a Google Map show the small GMaps pin on the thumbnail. Here is a sample. Check out the Zoomr wiki!
Attendr.com + Google Maps - gives people a way to connect up and find out about each other before a conference or party, and then to follow up with them afterwards. The unique part is that you can see the relationships between people on the map, and also see the tag connections.
GeoNames.org + Wikipedia entries + Google Maps - A mashup with over 140,000 entries in 185 languages. For English and German a short summary of the wikipedia text is available and will be displayed as the user clicks on a mark.
Technorati Tags: [Web 2.0], [Google Maps API], [Google], [Google Local], [Google Maps mashup], [Google Maps], [Google Maps Mania]