Hi, my name is Björn Brala. In the last two years, I've been working on GeoStart, a framework based on the Google Maps API. In that time, the developer community has been an invaluable source of information and help.
When the Google Maps API V3 was released, we were asked to port V2 utility libraries over to work with V3. Since I enjoy challenges, I decided to port over the MarkerManager library. After some rigorous testing and help from Daniel Lee, one of Google's Developer Programs Engineers supporting Geo APIs, I succeeded!
For those who are not familiar with MarkerManager, it's a class originally created by Doug Ricket that manages the additions and removals of many markers when the viewport changes.
Since real code can sometimes speak a thousand words, here's a basic Weather Map example which uses the MarkerManager class. This map creates a random collection of weather markers. When you zoom in, more weather markers are displayed to show more detailed local weather.
If you want to see more examples coupled with detailed explanations on how to use the code, visit the examplespage and the reference guide, which are both hosted in the Google Maps Utility Library V3 project.