In July Google Maps gained a new button that, when clicked, centres the map on your approximate location.
Also in July the Google Maps for Flash API released 3D view. Street View added some cool navigation tools to use with user-contributed photographs (very similar to Microsoft's Photosynth).
Google Maps for Mobile 3.2 added a number of new layers, including traffic, local search results, Latitude friend locations and Wikipedia.
Google released a collection of favourite places around the world chosen by local celebrity experts. The Favorite Places site features a Google Map with locations chosen by each of the celebrities.
Real estate listings were added to Google Maps in Australia and New Zealand.
In August Google started adding interactive markers to businesses and points of interest in Street View.
The Google Maps team released v2 of the API for Google Static Maps. The release added a number of new features including polylines and polygons.
Google also added traffic conditions on arterial roads in selected cities on Google Maps.
In August Street View was launched in Switzerland and Portugal. Also Picassa photographs were added as a source for user-contributed photos in Street View.
Google added Polylines and Polygons to the Maps API v3.
In August Google also added Place Pages to Google Maps. To get to a Place Page you can click on the 'more info' link that appears when you carry out a search in Google Maps.
In October driving directions were added to the Google Maps API v3.
Google Maps also released a new base map dataset for the USA. Google ended its partnership with TeleAtlas for US map tiles. Which paved the way for Google to release Google Maps Navigation.
In October the biggest news was undoubtedly the release of Google Maps Navigation (Beta) for Android 2.0 devices.
Google Maps Navigation comes with everything you'd expect to find in a GPS navigation system, like 3D views, turn-by-turn voice guidance and automatic rerouting.
Google rolled out some design changes to the map and hybrid views in Google Maps. These included refinements to color, density, typography, and road styling.
In October Google also released Street View in Canada.
In November Google added some new features to its location tracking service Google Latitude. The main new feature was Google Location History, which allows you to store your past locations and visualize them on Google Maps and Earth.
Google released Street View in Mexico, Hawaii and expanded coverage in the Netherlands and Spain.
In December Google released Google Goggles. Google's new Android phone application, Google Goggles, allows mobile phones to carry out visual searches, using images rather than text. Users take a picture of something with their camera phone and Google will return results based purely on the photograph.
In December Google also released 'Aerial View' in the Google Maps API. 'Aerial View' provides oblique views on Google Maps. Aerial View imagery is limited to San Jose and San Diego for now but Google has plans to add new imagery over the coming months.
For now Aerial View is only available through the Google Maps API but in 2010 I'm pretty sure it will graduate to the main Google Maps site.