These mini-applications, called Mapplets, make it possible for users to view and layer maps containing information such as real estate listings, jogging trails, events and photos.

For example, users who are planning a vacation can now view and layer maps of hotel availability, regional weather forecasts, gas prices and other useful information directly in Google Maps. Once they have created their custom map, they can create their own personalized itinerary by saving the results, adding their own notes, and putting it on a map to share with family and friends. Users looking for a new home can not only search real estate listings, but they can also layer their findings over transit maps and crime statistics to further refine their search.

These new tools can be found in the Google Maps Directory. The directory is accessed by clicking on the "Add content" link in the "My Maps" tab in Google Maps. Users simply click on the "Add it to Maps" buttons within the directory to bookmark relevant content.

Over 100 Mapplets are currently featured in the Google Maps Directory:

Hotel pricing and availability from Orbitz and Booking.com 
Enlarge image Live, local weather conditions and traffic cameras from WeatherBug
Worldwide webcams from Webcams.travel
Things to do and local events from Zvents
Gas prices from GasBuddy.com

Google has also developed several Mapplets:

Google Real Estate Search -- Find rentals and homes for sale in the US; this Mapplet draws from listings in Google Base
YouTube Videos -- Watch recently uploaded YouTube videos from around the globe
Photos from Panoramio -- See photos of locations from Panoramio.com while you browse Google Maps

These tools are built using the Google Mapplets platform, which enables any developer to create mini map applications that overlay their content on Google Maps and showcase their services to millions of Google users. Developers can find more information on authoring Mapplets here: http://www.google.com/apis/maps/documentation/mapplets/

This new functionality is available for Google Maps users in the US, the UK, Canada, Australia, France, Italy, Germany, Spain, Netherlands, Denmark, Finland, Norway, Sweden and Russia. It is available in the following languages: English, French, Italian, German, Spanish, Dutch, Danish, Finnish, Norwegian, Swedish, Russian and Chinese (TW).