When we were building the original Google Maps site, we envisioned that it would eventually become a platform for navigating all kinds of location-based information, such as home listings and travel information. Within weeks of the launch of Google Maps, we were pleasantly surprised that an independent developer named Paul Rademacher released HousingMaps.com, a site that displayed housing listings from Craigslist on top of our interactive maps -- what is now known as a "mashup" -- without needing help from anyone at Google. Hoping to encourage even more of this type of innovation, we released the official Google Maps API in June 2005, and since then, developers have created over 50,000 Google Maps mashups.

However, we noticed many of these mashups simply displayed a static set of places on a map, such as the best bars in San Francisco, yet the authors had to set up a website and write Javascript code to generate the map, which is not something that we could expect the average person to do. We also noticed that much of this great content was not getting discovered, even though millions of users were coming to Google Maps every day and searching for [bars] and [homes for sale].

To address these issues, we started two major projects:

In April, we released the first version of "My Maps," which empowers anyone to create a personal map simply by dropping placemarks onto the map. These maps are hosted on Google Maps and can be shared with friends and family. When marked as "public," these maps are automatically included into the Google Maps search index so that other users can find them. Since the launch of the "My Maps" tab, over 4 million maps have been created.

While this drag-and-drop editor is a great tool, we still needed a solution to help with mashups that have dynamic content such as real-time weather conditions. Thus, we created the Google Mapplets platform, which enables any developer to create mini applications that overlay their content and services onto Google Maps. We announced a preview version of Mapplets in May, and over 100 developers submitted Mapplets within the first month.

Today, we've brought these two features together under the "My Maps" tab on Google Maps. You can now layer information from multiple sources on the same map as well as save content that's relevant to you into a personal map. For example, if you're looking for a home in Chicago, you can add Mapplets that display real estate listings and Chicago Transit Authority train lines so that you can find out which homes are near public transit. To get an even richer sense of the surroundings, you could also layer in photos of the neighborhood and local events (from Zvents). When you find a home that you're interested in, simply click on "Save to My Maps" in the home's info bubble and save a copy of it to your personal map.

To get started, check out this demo video and then head over to the "My Maps" tab to find great maps and tools you can add from the Google Maps Directory.